What are the most common reasons for missing your period when you’re not pregnant? In this article, I’ll explain the top 16 reasons why you might be skipping your period this month.

Let’s face it – missing your period is honestly one of the scariest feelings, especially if you don’t want to be pregnant. I’ve missed a few periods in my lifetime, and it always makes my heart skip a beat. Before I was married, the thought of being pregnant was literally the worst idea ever. 

For a majority of women, missing a period is often the first sign that you’re pregnant. First thing’s first, go buy and take a home pregnancy test immediately. I’d recommend taking at least 2 to be sure. 

After my wedding and honeymoon last year, the last thing I wanted to be was pregnant. I’ve been tracking my cycles pretty religiously since 2008, and my period was due to arrive. Then it didn’t come. I freaked out, and I took a pregnancy test right away. 

And it was positive. 

The Plus sign was slow to appear right away, so I went and bought another pregnancy test later that day. It was a digital one with the words “pregnant” clearly labelled.  

So, if you’ve missed your period, take a home pregnancy test IMMEDIATELY. Different HPTs have varying levels of sensitivity to hCG (the pregnancy hormones), so if you take one test and it’s negative, wait a day or two, buy another brand and take another one. 

I’d also recommend calling your doctor or healthcare provider and getting a urine pregnancy test in their office, if you’re worried that the home pregnancy tests are inaccurate. 

Many non-pregnancy reasons for a missed period or irregular periods are benign and aren’t serious health concerns. In a majority of cases, they’re caused by a hormonal imbalance, and this imbalance can be easily treated by your medical doctor or healthcare provider.  

It can be normal to miss an occasional period here or there. Most OB/GYNs and other women’s healthcare providers don’t worry about a missed period until it becomes a pattern (you’ve missed three periods in a row, or three missed period throughout the course of one year.)

If you’ve missed three periods, make an appointment with your doctor right away.

Amenorrhea – An Absence of Menstruation 

The medical term for a missed period, or an absence of a menstrual period is called an amenorrhea. There are two kinds of amenorrheas:

Primary Amenorrhea – The medical definition of primary amenorrhea is the failure to achieve menstruation. Basically, your body is incapable of naturally having periods.

This may be due to genetic or chromosomal irregularities that have caused you to have ovarian insufficiency. For example, Turner syndrome can cause you to have primary amenorrhea. 

Anatomic abnormalities in your reproductive organs can also cause you to not have a period. You may have been born without a uterus, or possibly the uterus didn’t develop normally.

If you’re a teenager, and you haven’t had your period by age 13 and if there are no signs of puberty (such as breast growth), you should contact a gynecologist to get checked out. 

In some cases, secondary amenorrhea (discussed below) can trigger primary amenorrhea.

To learn more about primary amenorrhea and how it’s diagnosed and treated, visit the American Family Physician’s medical article about it: Amenorrhea: An Approach to Diagnosis and Management 

Secondary Amenorrhea – If you have missed your period for three months in a row, then you’d fall into this category of amenorrhea. Secondary amenorrhea also includes the disappearance of irregular cycles for six months or more.

In many cases, secondary amenorrhea is caused by by polycystic ovary syndrome, premature ovarian failure, hypothalamic amenorrhea (a problem with the hypothalamus of your brain causing you to miss periods), and possibly hyperprolactinemia (you have an abnormally high level of the hormone prolactin in your body). I’ll go into these in more detail below.

Generally, physicians won’t diagnose or look further into why you’ve missed your period until you’ve had an absence of any menstruation for three months or longer. 

Another medical term you might want to be familiar with is Oligomenorrhea. Doctors use this word for women who have less than eight menstrual cycles per year. The causes for oligomenorrhea are the same as secondary amenorrhea, though most women with oligomenorrhea have polycystic ovary syndrome.

When in doubt, make an appointment with your physician or healthcare provider and get answers. 

Reasons for a Missed Period

This is the last thing you want to hear, but unfortunately (or happily for some women), the most common reason for a missed period is pregnancy. Before you read on, you’ll want to rule out that you’re pregnant. Take a home pregnancy test right away on the day of your missed period.

Today’s home pregnancy tests are 99% accurate when tested on the first day of your expected period. Some tests, such as First Response Early Pregnancy Test claim that you can get a positive result as early as six days before your period.

Just be careful about testing too early – it may cause you to have an inaccurate result. You might test negative when you are in fact pregnant, because there’s not enough pregnancy hormone in your urine yet. Or you could test positive, but then get your period later on.

The First Response Early Pregnancy Test is my favorite brand of HPTs. It’s one of the more sensitive tests on the market with hCG levels at 25mIU/ml, so it can possibly detect pregnancy immediately after the fertilized egg implants in your uterus. Read the fine print on any over-the-counter HPT and it should tell you how sensitive it is to the hCG hormone, which only secretes during pregnancy. The lower the number of mIU/ml, the more sensitive.

Okay, you’ve done your due diligence and you’ve taken multiple home pregnancy tests on different days, and you’re totally not pregnant. What are some of the other reasons why you’ve skipped your period this month?

1.) You Didn’t Ovulate This Month

Not every woman ovulates every month. When you don’t ovulate, your ovaries don’t release an egg and your uterus has nothing to shed, so you’ll either have spotting or a very light period, or you won’t get your period at all. Aunt Flo is on vacation until next month.

Thirty percent of infertility cases are caused by anovulation (a fancy term for when you don’t ovulate during a menstrual cycle.). Anovulation can be caused by many reasons, some of which I will discuss in this article.

About 70% of women who suffer from anovulation have polycystic ovarian syndrome. If you have this syndrome, you will have irregular periods. Other reasons why you didn’t ovulate this month include hypothalamic-pituitary imbalance, thyroid problems, stress and anxiety, and long-term use of hormonal birth control.

2.) Polycystic Ovarian Syndrome

You have polycystic ovarian syndrome. It’s possible to suffer from PCOS and not even realize it. Women with this illness first notice symptoms in their late teens or early 20s. Some of the symptoms are just part of normal puberty and may be overlooked at first.

Symptoms of polycystic ovarian syndrome include acne, hirsutism (male-pattern hair growth on your face, chest, back, or butt), and irregular periods (skipped periods, or menstrual cycles longer than 35 days). PCOS can also make you gain weight and have hair loss. Women with PCOS also suffer from irregular ovulation, or a failure to ovulate.

One-third of women with this syndrome are overweight. In women who have polycystic ovarian syndrome, obesity increases their risk of not ovulating and having missed periods.

3.) Weight Problems (Being Underweight and Overweight)

Related to polycystic ovarian syndrome are weight problems, which can be another cause of missed periods unrelated to pregnancy.

If you’ve had any substantial fluctuations in your weight recently – either you’ve lost a bunch of weight, or you gained a lot of weight – this can also explain why you’ve skipped your period this month.

In order for your body to do its job properly and have a healthy menstrual cycle, you need to have a balance of body fat.

Your sex hormones are stored in your body’s fat layers. If you have too little or too much, your reproductive hormones, such as estrogen, can be thrown out of whack and this can affect your cycle and your fertility. It may be hard for you to conceive if you are either underweight or overweight.

Women who are underweight, with a low BMI, may produce a lower level of estrogen needed for reproduction, which can lead to you not ovulating and not having a period.

Similarly, being overweight or obese can also affect your estrogen levels. Overweight women may produce too much estrogen. This overabundance of estrogen can lead to anovulation and missed periods. It can also lead to polycystic ovarian syndrome (PCOS, which is discussed above). With PCOS, your body produces too much estrogen and too much androgens (male hormones).

4.) Hormonal Birth Control

* Please note that this article provides generic information about menstrual cycles, birth control, and periods. If you have specific questions, ask your healthcare provider. * 

There are many different types of hormonal birth control that you can choose from, including long-acting contraceptives, such as IUDs and other hormonal implants, as well as the birth control pill, shot, or a vaginal ring. Some of these are commonly known to cause missed periods. 

For example, a copper intrauterine device like ParaGard can cause missed periods, bleeding in between periods, and heavier flow cycles.  

Other hormonal IUDs, such as Liletta, Mirena, and Skyla can also cause lighter flows, missed periods and irregular periods. 

Other hormonal birth control methods, such as the birth control injection (Depo-Provera) and the birth control implant (Implanon and Nexplanon) can cause you to have irregular periods and missed periods.

With the Depo-Provera birth control shot, you may have no periods at all or irregular menstrual periods. It’s common to have missed periods and bleeding between periods with the Depo-Provera injection. In 50 percent of cases, women who receive regular injections will stop having their periods after 12 months. 

If you are planning to start a family, you may want to choose another birth control method. Although some women can get pregnant three to four months after their Depo-Provera injection, it may take some women up to two years after they stop getting the injections before they can conceive.

Now let’s talk about Birth Control Pills.

Today, you have two main options when it comes to birth control bills: the mini pill (which contains progestin only) and the combination pill (which have both estrogen and progestin). 

Although the mini pill doesn’t contain estrogen, a common side effect of this type of birth control pill is irregular bleeding. Although many women who take mini pills experience normal periods, some others don’t have periods at all, or they may have missed periods, irregular menstrual cycles, spotting in between their cycles.

Combination birth control pills change your menstrual cycle regularity, so missed periods are common with these hormonal contraceptives.

Amethyst (formerly called Lybrel), for example, was one of the first extended-cycle oral contraceptives. It prevents ovulation, so you won’t have a period while on this pill, but you may have breakthrough bleeding and spotting when you least expect it.

With some extended cycle birth control pills, you will still have a period but not as often.

For example, with Seasonique, you only have four periods each year. Each pack will last you three months, and you get your period the last week of the pack (so a period every 3 months). Like with the other birth control pills, you will experience spotting and bleeding between periods – called breakthrough bleeding.

If you’ve just started taking a combination birth control pill, it’s perfectly normal for you to skip a period, or have a lighter period than normal. Some women only get a drop of blood or brownish staining; others don’t bleed at all.

Read your specific birth control package instructions and warnings about its side effects. When in doubt, take a home pregnancy test. Talk to your doctor or healthcare provider about specific questions regarding your specific birth control.

Here are some common side effects of birth control brands you may have heard about:

With Lo Loestrin Fe, you have regular periods, but they are shorter in length. However, roughly half of women using it will have a missed period before the year is over.

If you’re taking Sprintec or Yasmin, it’s common to experience spotting in between your cycles, as well as missed and irregular periods. These period problems are more common during the first few months of starting the pill.

Now let’s talk about the birth control patch and vaginal contraceptive rings!

With the birth control patch (Xulane), changes in your menstrual cycle are common. You may experience bleeding in between periods, like with the other birth control methods, especially during the first two months of using the patch. This unexpected bleeding will decrease in the first 6 to 12 months.

Using the NuvaRing can also cause your period to change. This vaginal ring may cause unplanned bleeding, such as breakthrough bleeding, and spotting in between periods. Some women will miss their period using the NuvaRing even when they aren’t pregnant.

5.) Your Hypothalamus is Malfunctioning

Missed periods can occur because something is wrong with the hypothalamus area of your brain. The medical term for this is hypothalamic amenorrhea.

The hypothalamus is the area in your brain, near the pituitary gland, that produces important reproductive hormones, in particular the gonadotropin-releasing hormone (GnRH). GnRH signals the production of the follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which then tell your ovaries to produce estrogen.

Estrogen is crucial in a healthy reproductive system, as this is the hormone that thins out the cervical mucus and (in conjunction with the hormone progesterone) prepares your uterus to receive a fertilize egg so that pregnancy can occur.

When the hypothalamus works correctly, this beautiful cycle of hormones allows you to have normal periods. However, if the hypothalamus malfunctions and stops working properly, it can cause period problems and missed periods.

When the hypothalamus malfunctions, it may stop the production of the gonadotropin-releasing hormone (GnRH), which then reduces how much FSH, LH, and estrogen are produced, which then prevents ovulation from occurring. This, you may have irregular cycles or no menstrual period.

6.) Too Much Prolactin In Your Bloodstream

You may have a condition called hyperprolactinemia, in which your prolactin levels are too high and this can affect your menstrual cycles negatively.

The hormone prolactin is produced by the pituitary gland – and if you’ve been paying attention, this gland plays a crucial role in maintaining a healthy reproductive system. Prolactin stimulates your milk production after you have a baby.

Everyone has small amounts of prolactin in their bloodstream. In non-pregnant women, this hormone helps regulate their periods. However, if you have high prolactin levels, this can cause you to have period problems.

When your prolactin levels are too high, they will negative effect the production of estrogen and progesterone, which can affect ovulation, possibly preventing it, which can lead you to have a missed period.

High prolactin levels can be caused by a tumor of the pituitary gland (a condition called prolactinoma), an underactive thyroid, as well as the unwanted side effects of certain medications, like antipsychotics. Herbs such as fenugreen, red clover, and fennel seeds may also trigger hyperprolactinemia.

Roughly one-third of women who have irregular periods suffer from hyperprolactinemia. You may not experience any symptoms at all.

If you have any questions or want to get tested for this condition, contact your healthcare provider.

7.) Pituitary Tumors

Related to hyperprolactinemia, pituitary tumors can cause you to miss your period or have irregular cycles. Although it’s scary to hear the word “tumor,” these are non-cancerous and benign.

Because your pituitary gland produces the reproductive hormones – FSH (follicle-stimulating hormone) and LH (luteinizing hormone), which trigger estrogen production in your ovaries – a pituitary gland tumor (called a prolactinoma) can be the reason you are experiencing missed periods.

If you have a prolactinoma, you may have symptoms, including irregular periods, missed periods, or no periods, milky discharge from your breasts (and you are not breastfeeding), no interest in sex, and pain during sex because of vaginal dryness.

8.) Perimenopause

At some point in a woman’s life, she will go through menopause. Depending on the woman, she may start going through her change as early as age 45 and as late as 55. In the United States, the average age is 55.

When you hit menopause, this is the end of reproductive life. You stop having periods and you can no longer get pregnant.

However, menopause doesn’t just happen overnight – you won’t have a period one day and bam, hit menopause overnight. It starts with perimenopause.

Sometimes called your menopause transition, perimenopause can cause your periods to act super erratic. As your body gears up for the end of menstruation, your ovaries start to produce less estrogen and this can cause all kinds of problems with your cycle. For example, during perimenopause, you may have super heavy periods one month, then a skipped period the next.

If you’re in your 40s, perimenopause is a very common reason for a missed period when you’re not pregnant.

The first sign of perimenopause is irregular menstrual cycles. Perimenopause can also cause hot flashes and vaginal dryness. On average, perimenopause lasts three to four years. However, every woman’s body is different. Some women go through their transition quickly, experiencing menopause only for a few months. Other women experience perimenopause, along with erratic periods, for a decade.

Even though your ovaries are declining, you can still get pregnant while going through perimenopause. So take a home pregnancy test if you’re sexually active.

9.) Early or Premature Menopause

If you’re too young for perimenopause, another common reason for a skipped period is early or premature menopause.

If you enter menopause before you reach 45, it’s called early menopause.

If you go into menopause before age 40, they call it premature menopause.

This can occur naturally (due to family history).Certain medical conditions (such as autoimmune disease, thyroid disease, chromosomal problems, and chronic fatigue syndrome) can also cause early or premature menopause. Surgeries to remove your reproductive organs (such as a hysterectomy and bilateral oophorectomy) also make you enter menopause, as well as chemotherapy and radiation treatments for cancer.

With early or premature menopause, your body stops producing the hormones needed for ovulation (like estrogen and progesterone). Your periods disappear forever because your reproductive years are over.

10.) Premature Ovarian Failure

If you’re younger than 40 and you’re experiencing missed periods and an erratic menstrual cycle, premature ovarian failure could be the culprit.

Premature ovarian failure – also called primary ovarian insufficiency – occurs when your ovaries stop working before age 40.

Women with premature ovarian failure have irregular periods, missed periods, and reduced fertility. Their ovaries can begin to fail as early as their teen years.

Often confused with early or premature menopause, women with premature ovarian failure can still have periods. It is possible for them to get pregnant on the months that they ovulate. With early or premature menopause, women do not have periods and are no longer fertile.

11.) Your Age

Related to perimenopause and all the reasons above, your age plays a role in your fertility. As you get older, you become less fertile. According to the American College of Obstetricians and Gynecologists, you fertility undergoes a rapid decline by the time you reach your mid-30s.

For a healthy woman in her 20s and early 30s, she has a 25 percent chance of getting pregnant in any menstrual cycle. By the time she reaches 40, she only has a 10 percent chance.

As you get older and your fertility declines, it’s probable for you to experience a missed period here or there.

12.) Stress

Stress takes its toll on your body. It has so many negative effects, including lowering your immune system and making it more likely for you to catch illnesses, increasing your risk for heart attacks and strokes, and it can also negative impact your reproductive system and cause you to have a missed period when you’re not pregnant.

Your menstrual cycle is regulated by a delicate balance of hormones, and anything that affects the release of those hormones will affect your cycle. Stress interferes with the regular functioning of the hypothalamus in the brain; the “command center” of the brain that produces hormones that regular your menstrual cycle, sex drive, moods and emotions, and more.

When you are stressed, your body perceives danger (“fight or flight” response) and it sends a warning call to your hypothalamus – the command center of the brain. The hypothalamus sets off a “Danger! Danger! Danger!” alarm and sends it to your pituitary gland, which then secretes a hormone called adrenocorticotropic hormone, which in turn stimulates your adrenal glands to release cortisol (the “stress hormone”) and adrenaline.

The activation of the body’s stress response can disrupt your body’s normal processes, including the regulation of your menstrual cycle. Your body is so focused on handling the perceived danger that other normal bodily functions get put on the back burner.

Stress can delay ovulation. The pituitary gland – which is very involved with how your body handles stress – releases the luteinizing hormone (LH) and the follicle-stimulating hormone (FSH), which are both crucial hormones during your menstrual cycle. FSH plays an important role in helping your egg mature in the ovary, and LH is the hormone that triggers the mature egg’s release from the ovary during ovulation.

Basically, when the pituitary gland is overwhelmed by handling your body’s stress level, you may have a delayed or late ovulation, or no ovulation and no period this month.

13.) Breastfeeding

If you are exclusively breastfeeding – meaning that your milk is your baby’s only source of food – you usually don’t have periods. This is called lactational amenorrhea. 

Once your baby starts eating solids and you decrease how much you breastfeed, your period start to rear its ugly head. Nearly all mothers who breastfeed full-time will delay their periods by 3 to 6 months, or possibly longer.

(In my personal experience as a full-time exclusive breastfeeder, my period returned at 5 months postpartum when my son started to eat more solid food.)

Once your period returns and you are still breastfeeding, it’s not uncommon for you to have skipped periods, or go several months in between periods.

When you reduce how much you breastfeed, your periods will soon return to normal.

14.) Thyroid Problems

Thyroid disease, such as hyperthyroidism and hypothyroidism, can dramatically affect your cycle. It can cause your periods to become irregular, heavier than normal, and it can also cause amenorrhea (no periods for a few months or longer.)

Thyroid disorders affect the production of prolactin, which makes your hypothalamus malfunction and leads to a disruption in your cycle. As a result, you may have missed periods and irregular menstrual cycles.

Both hypothyroidism and hyperthyroidism can cause missed periods.

Hypothyroidism, also called an under active thyroid, can make your body produce excess prolactin, which prevents ovulation causing a missed period.

Hyperthyroidism, another name for an overactive thyroid, can cause you to have lighter and fewer periods than normal.

15.) Uterine Scarring, and Asherman Syndrome

If you have uterine scarring, it can cause irregular menstrual cycles and possibly a missing period. Uterine scarring that causes symptoms is called Asherman Syndrome. It is considered a rare condition, but it does occur and is worth mentioning.

Your uterus may be scarred due to an infection, such as endometritis (an infection in your uterine cavity), tuberculosis, and chlamydia.

In many cases, Asherman Syndrome occurs after a dilation and curettage procedure for an abortion, an incomplete miscarriage, or to medically remove a placenta after delivery. You may also have uterine scarring from a C-section or a surgical procedure to remove fibroids.

Common symptoms of Asherman Syndrome includes very light periods or no periods.

16.) Traveling and Jetlag

The jetlag that comes with traveling can sometimes wreck havoc on your menstrual cycle. Jetlag affects your body’s circadian rhythm, which regulates more than just your sleep-wake cycle, but also hormone release in your body.

In fact, did you know that female flight attendants

According to a study published in the May 1980 issue of the medical journal, Aerospace Medicine and Human Performance, about 39% of female flight attendants experience changes in their menstrual cycles. It’s believed that the disruption in their circadian rhythm caused these changes.

What To Do If You Miss a Period

If you have missed your period, take a deep breath. Take a home pregnancy test. Contact your healthcare provider if you are worried something might be wrong.

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Sources for Further Reading:

“Asherman’s Syndrome, Adhesions.” Cleveland Clinic, my.clevelandclinic.org/health/diseases/16561-ashermans-syndrome.

“Asherman’s Syndrome.” NORD (National Organization for Rare Disorders), rarediseases.org/rare-diseases/ashermans-syndrome/.

Breakthrough Bleeding | Lo Loestrin® Fe, Lo Loestrin® Fe, www.loloestrin.com/about-lo-loestrin-periods.

“Breastfeeding and Periods.” Healthdirect, Healthdirect Australia, www.healthdirect.gov.au/breastfeeding-and-periods.

“Circadian Rhythms.” National Institute of General Medical Sciences, U.S. Department of Health and Human Services, www.nigms.nih.gov/Education/Pages/Factsheet_CircadianRhythms.aspx.

“Early or Premature Menopause.” Womenshealth.gov, 22 May 2018, www.womenshealth.gov/menopause/early-or-premature-menopause.

Hamilton-Fairley, Diana, and Alison Taylor. “Anovulation.” BMJ (Clinical Research Ed.), BMJ Publishing Group Ltd., 6 Sept. 2003, www.ncbi.nlm.nih.gov/pmc/articles/PMC192851/.

Harvard Health Publishing. “Perimenopause: Rocky Road to Menopause.” Harvard Health, www.health.harvard.edu/womens-health/perimenopause-rocky-road-to-menopause.

“Hyperprolactinemia (High Prolactin Levels).” Reproductive Facts, www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/documents/fact-sheets-and-info-booklets/hyperprolactinemia-high-prolactin-levels/.

“Hypothalamic Amenorrhea.” Shady Grove Fertility, www.shadygrovefertility.com/diagnosing-infertility/infertility-causes/female-infertility-causes/hypothalamic-amenorrhea.

Iglesias, R, et al. “Disorders of the Menstrual Cycle in Airline Stewardesses.” Aviation, Space, and Environmental Medicine, U.S. National Library of Medicine, May 1980, www.ncbi.nlm.nih.gov/pubmed/7387577.

Klein, David A., and Merrily A. Poth. “Amenorrhea: An Approach to Diagnosis and Management.” American Family Physician, 1 June 2013, www.aafp.org/afp/2013/0601/p781.html.

Kulshreshtha, Bindu, et al. “Menstrual Cycle Abnormalities in Patients with Prolactinoma and Drug-Induced Hyperprolactinemia.” Indian Journal of Endocrinology and Metabolism, Medknow Publications & Media Pvt Ltd, 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5477442/.

Meczekalski, B, et al. “Functional Hypothalamic Amenorrhea and Its Influence on Women’s Health.” Journal of Endocrinological Investigation, Springer International Publishing, Nov. 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC4207953/.

“NuvaRing Frequently Asked Questions.” NuvaRing® (Etonogestrel/Ethinyl Estradiol Vaginal Ring), www.nuvaring.com/frequently-asked-questions/.

“Primary Ovarian Insufficiency | POI.” MedlinePlus, U.S. National Library of Medicine, 13 Sept. 2019, medlineplus.gov/primaryovarianinsufficiency.html.

“Progesterone-Only Oral Contraceptives (Minipills).” Cornell Health, 18 Oct. 2019. https://health.cornell.edu/sites/health/files/pdf-library/MiniPills.pdf

Silva, Juneo F, et al. “Thyroid Hormones and Female Reproduction.” Biology of Reproduction, U.S. National Library of Medicine, 1 Nov. 2018, www.ncbi.nlm.nih.gov/pubmed/29767691.

Silva, Juneo F, et al. “Thyroid Hormones and Female Reproduction.” Biology of Reproduction, U.S. National Library of Medicine, 1 Nov. 2018, www.ncbi.nlm.nih.gov/pubmed/29767691.

Smikle, Collin. “Asherman Syndrome.” StatPearls [Internet]., U.S. National Library of Medicine, 6 Nov. 2019, www.ncbi.nlm.nih.gov/books/NBK448088/.

“Understanding Infertility.” Fertility Clinic, Infertility Specialists | Southern California Reproductive Center, www.scrcivf.com/understanding-infertility/body-fat-exercise-fertility/.

UpToDate, www.uptodate.com/contents/polycystic-ovary-syndrome-pcos-beyond-the-basics.

Villavicencio, Jennifer, and Rebecca H Allen. “Unscheduled Bleeding and Contraceptive Choice: Increasing Satisfaction and Continuation Rates.” Open Access Journal of Contraception, Dove Medical Press, 31 Mar. 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC5683158/.

“What Birth Control Method Is Right for You?” Womenshealth.gov, 14 Feb. 2019, www.womenshealth.gov/a-z-topics/birth-control-methods.

“Women’s Health Care Physicians.” ACOG, www.acog.org/Patients/FAQs/Having-a-Baby-After-Age-35-How-Aging-Affects-Fertility-and-Pregnancy?IsMobileSet=false.

Ziomkiewicz, et al. “Body Fat, Energy Balance and Estradiol Levels: a Study Based on Hormonal Profiles from Complete Menstrual Cycles.” OUP Academic, Oxford University Press, 18 July 2008, academic.oup.com/humrep/article/23/11/2555/2913840.