What are the reasons for a missed period when you’re not pregnant? For most women, a missed period is typically the first sign of pregnancy. But what can cause a missed period (or a late period) if you’re not pregnant? There are many reasons that cause your period to be late.
(You may also like to read about PMS or Pregnancy? A related article that compares PMS symptoms to the very first pregnancy signs.)
Normal Menstrual Cycles & Lengths
In general, a woman can expect to have 11 to 13 menstrual periods every year. That is, if you have a regular menstrual cycle that runs like clockwork, month after month. An average period can last anywhere from three to five days; it can be shorter or longer than this, but it’s typically no longer than 7 days or a week.
A textbook menstrual cycle is 28 days (from one period to the next; this is the average length of a period or menstrual cycle). However, it is very common for adult women to have menstrual cycles that range anywhere 21 to 35 days.
Teenagers – keep in mind that the first couple of years after your period starts, it’s normal to have long cycles (longer than 35 days). In adolescents and teenagers, a menstrual cycle can range anywhere between 21 and 45 days and still be considered normal.
Because there is variability for cycles, if you have a period that falls outside of the 35 day mark, don’t automatically assume the worse. Menstrual cycles can vary each month – a day or two late here, or a few days early there – for a number of reasons. As long as you have a period every month, you are probably fine. However, you will probably want to make an appointment with a gynecologist to get checked out if your cycle is over 40 days. My motto is that it’s always better to be safe than sorry!
Remember that what’s considered “normal” for one woman may be very different for another woman. If you ever have concerns, talk to your healthcare provider.
Causes for Missed Periods (Amenorrhea)
Most irregular periods and missed periods are typically benign and do not signal anything serious. They are often caused by a hormonal imbalance (your menstrual cycle works in conjunction to a delicate balance of hormones), and this imbalance is easily treated under the supervision and medical guidance of your doctor or healthcare provider.
So, it is normal to miss a period occasionally. A missed period should be examined in terms of what’s normal for your individual case.
Doctors and healthcare providers usually don’t worry about a missed period or two or three unless it becomes a pattern. It is highly recommended that you see a healthcare provider if you miss more than three periods – either consecutively (one right after the other) or three missed periods during the course of one calendar year. This might be a cause of concern.
A missed period, or an absence of a menstrual period is called amenorrhea in the medical world. Doctors have classified amenorrhea into two categories:
- Primary Amenorrhea - You’re 15 years old, and your periods haven’t started yet.This can be caused by conditions you were born with but aren’t noticed until you hit puberty – such as genetic or chromosomal abnormalities and problems with your reproductive organs. These might include being born without a uterus, or a uterus that did not develop normally. In some cases, the causes of secondary amenorrhea can also cause you to have primary amenorrhea.
- Secondary Amenorrhea - Your periods have suddenly stopped for more than three months, and you’ve had menstrual periods in the past.This is the most common form of missed periods, or amenorrhea.Secondary amenorrhea will be discussed in this article. Common causes for it include pregnancy, ovarian problems (like polycystic ovary syndrome and early menopause), pituitary tumors, stress and anxiety, having to little or too much body weight, and other reasons for missed periods.Usually, doctors will not diagnose you with secondary amenorrhea until you’ve skipped three periods in a row.
In addition to amenorrhea, there’s another medical term that you should be familiar with – Oligomenorrhea. This is a medical term for women who experience fewer than eight menstrual periods each year, or infrequent menstrual periods. The same causes for secondary amenorrhea can cause oligomenorrhea. However, most women with oligomenorrhea have polycystic ovary syndrome.
If you are ever worried about missing your period, take a home pregnancy test and make an appointment with your healthcare provider and seek answers!
Reasons for Missed Period When Not Pregnant
Pregnancy – The # 1 Reason for a Missed Period
So what are the common causes of a missed period?
In a majority of cases, if you have normal menstruation – you have your period without fail every single month – and you’ve missed your period, you are more than likely pregnant.
Here’s the reason – during your menstrual cycle, around the second week (day 7 to 14 before ovulation), your uterine lining grows thick with blood and nutrients in preparation to receive a fertilized egg. When there is no fertilized egg after ovulation, the blood-rich uterine lining, unfertilized egg, and all the tissues break down and gets shed from your body – this is your period.
So if you miss your period, and you’ve always had normal menstrual cycles and regular periods, you should get it checked out as you have a high chance of being pregnant. Having a missed period might mean that your thick uterine lining has received a fertilized egg, and a baby is growing inside your womb.
Despite popular misconception, there is absolutely no possibility of having your period during pregnancy. You can experience spotting, or light vaginal bleeding here and there when you’re pregnant, which can be confusing and trick you into thinking you are having a period, but it’s not a menstrual period. (Read my related article – Implantation Bleeding or Period?).
So if you’ve missed a period, always assume that you could be pregnant. Take a home pregnancy test and schedule an appointment with your doctor, gynecologist, or healthcare provider to confirm or deny that you are pregnant.
(Helpful Tip: Not all home pregnancy tests are created equal. Some are more sensitive than others. After researching HPTs and their sensitivities to hCG, the pregnancy hormone, I would recommend First Response Early Result Pregnancy Test. It’s one of the most sensitive home pregnancy tests you can find (hCG levels at 25mIU/ml), and may even detect pregnancy after the fertilized egg implants. The packaging on any over-the-counter pregnancy test will tell you how sensitive they are. The lower the number of mIU/ml, the more sensitive it is to the hCG hormone that detects pregnancy.)
Reasons for Missed Period if Negative Pregnancy Test
So you’ve tested for pregnancy and got a negative pregnancy test, what are the other reasons for a missed period when you’re not pregnant?
Your missed period may be a result of one of the following common reasons for a missed or late period:
Anovulation (You Don’t Ovulate) – Most Common Reason for Missed Period
Ovulation problems account for 30 percent of infertility cases, and they are one of the most common common reasons for a missed period. A majority of women who seek fertility help because they are not ovulating. A menstrual cycle in which your ovaries don’t release a mature egg and you don’t ovulate is called anovulation.
Anovulation (or not ovulating) can be caused by a wide range of problems – many of these causes are discussed later in this article. They include polycystic ovarian syndrome to thyroid problems to stress and anxiety. Long term use of hormonal birth control – which disrupt ovulation and prevent it from occurring – can also cause anovulation.
Polycystic ovarian syndrome accounts for 70 percent of anovulation cases.
Stress and Anxiety – Another Reason for Missed Periods
Being stressed is never good for your health or your body, and it can cause a variety of problems, everything from lowering your immune response to affecting your cardiovascular health. Stress is also one of the reasons for a missed period.
Because your menstrual cycle is regulated by a delicate and complex balance of hormones, anything that can alter the release of those hormones will also affect your periods. 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 other functions.
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 that uses the autonomic nervous system to communicate with the rest of your body. So basically, the hypothalamus sets off a “Danger! Danger! Danger!” alarm in your body. The hypothalamus sends this alarm to your pituitary gland, which then secretes a hormone called adrenocorticotropic hormone, which in turn stimulates your adrenal glands to release cortisol (commonly referred to as the “stress hormone”) and adrenaline.
It is all a very complicated process, but the activation of the body’s stress response can disrupt your body’s normal processes – like 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.
So, for example, it is very commonly known that stress delays 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. This process is super complicated, but when the pituitary gland is too preoccupied with handling your body’s stress, this can cause you to either have a delayed or late ovulation, or no ovulation that month at all. And when you have a later than normal ovulation, you will have a delayed period (or a menstrual period that occurs much later in the month than you expected). If you happen to not ovulate that month, due to stress levels, you will have a missed period, no period at all.
For all of these reasons, being stressed is a very common reason for missed periods, delayed or late periods, and more painful periods. In a nutshell, stress just screws up your periods.
Overweight, Underweight, and Weight Problems
If you have lost a substantial amount of weight recently, or on the other hand, you’ve gained some weight too fast, this is another common reason for a missed period when you’re not pregnant. Weight gain and weight loss are common causes for menstrual problems, such as a late period or a missed period.
For your body to have a healthy, normal menstrual cycle, you have to have a balance of body fat – not too much and not too little. Being overweight (too fat) and being underweight (too skinny) can cause you to have irregular periods. Your body’s fat cells are responsible for your estrogen production. Estrogen plays a crucial role, along with luteinizing hormone and the follicle-stimulating hormone, to help the eggs in your follicle mature and then get released from the ovaries.
So if you don’t have enough fat cells, you may not ovulate due to not enough estrogen production, and you may have missed periods and irregular menstrual cycles. Similarly, being overweight can also affect your menstrual cycle.
Overweight women have an excess of fat cells in their body, which causes too much estrogen to be produced. Unfortunately, with these high levels of this female hormone, your body might react to this overabundance of estrogen like it’s birth control. As a result, you may not ovulate every month, which means you will have missed periods on a regular basis, or you may have no periods at all. It is also possible that you go months without having your period.
Too many fat cells and too much estrogen can cause many obese and overweight women to suffer from polycystic ovary syndrome (PCOS) – a condition in which your body produces too much estrogen and too much androgens (male hormones). PCOS has a genetic component to it, so you are more likely to have the condition if other women in your family have suffered from it. Women with PCOS tend to either have no periods at all, or heavy, irregular periods that can be painful. PCOS can cause infertility and small cysts to grow on the ovaries.
Contraceptives and Hormonal Birth Control
If you are taking hormonal birth control pills, it is not uncommon for you to experience light periods or no period at all – a missed period. If you’ve been taking your pills religiously and you miss your period, you are probably not pregnant, but if you are worried, take a home pregnancy test.
Some of the newer birth control pills on the market today – such as Lybrel, Seasonale, Seasonique, Yasmin, Yaz – are combination birth control pills, which change your menstrual cycle regularity. Missed periods are common with these hormonal contraceptives.
Lybrel, for example, is one of the first extended-cycle oral contraceptives, which gives you an active dose of hormones every day, and this birth control pill will stop you from having a period indefinitely, as long as you take it, because it inhibits ovulation. It purposely causes missed period. No ovulation; no period. Lybrel, however, does come with the risk of breakthrough bleeding and spotting when you least expect it.
With the other 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, because each pack will last you three months, and you should experience your period the last week of the pack. Like with the other birth control pills, you will experience spotting and bleeding between periods – called breakthrough bleeding. Seasonale also only gives you four years each year.
You have a monthly period with Yaz, but it’s a shorter and lighter menstrual flow. Yasmin also gives you a lighter, monthly period.
Keep in mind, however, that when you stop using birth control pills, sometimes it can take some women anywhere from one to two months to up to half a year before you become fertile again, because their bodies have to re-adjust to being without the hormones. Some women are fertile right away, but for others, it can definitely take awhile before your body re-adjusts to its normal hormones and functions.
Ovulation and menstruation can sometimes take a few months (or longer) before they return to normal. So you can expect missed periods during this transition.
Other hormonal birth control methods, such as the birth control shot (Depo-Provera) and the birth control implant (Implanon and Nexplanon) can cause you to have irregular periods and missed periods.
The Depo-Provera birth control method can cause you to experience irregular menstrual bleeding. In fact, irregular menstrual periods and no periods at all (missed period) is a common side effect of the birth control shot. In addition, it is common in 50 percent of cases; women who get regular birth control injections will stop having their periods after a year of use. However, if you are planning to start a family in the near future, you should probably think about avoiding the Depo-Provera injection. Although some women can get pregnant three to four months after their last injection, it can take other women up to one or two years after they stop getting the injections before they can get pregnant.
Breastfeeding and Missed Periods
Breastfeeding is another common reason for missed periods. When you are breastfeeding exclusively – meaning your baby is not getting his or her food source from anything else but your breast milk – this will usually delay your periods from returning.
You may have heard that breastfeeding is considered a natural form of birth control; this is why.
Prolactin, the hormone that stimulates your milk production, decreases your level of estrogen, so you do not ovulate. This breastfeeding hormone also affects luteinizing hormone (LH) secretion in your body; a critical hormone that triggers ovulation. As a result, you will experience irregular and missed menstrual periods when you are exclusively breastfeeding.
An estimated 80 percent of women who choose to bottle feed their babies will get their periods back after 10 weeks of delivery. If you are breastfeeding, you will experience more of a delay in the return of your periods. It could be ten weeks or one year, depending on each woman. However, on average, it takes breastfeeding moms about six months to become fertile again. This doesn’t always mean that your period has returned; it just means you’re fertile.
Your menstrual periods will return sooner when you aren’t feeding your baby as much. Maybe your infant has started to eat solid foods, or you’re supplementing with formula instead of exclusively breast milk.
If you are worried about getting pregnant again, start using birth control. Pay attention to your cervical mucus. Get some hormone tests performed at your doctor’s office to see if you are ovulating, but just not having your period yet.
It’s common for you to have irregular cycles and missed periods for the first couple of months after your period returns, after having a baby.
Pituitary Tumors (Non-Cancerous Tumors)
Although the word “tumor” is pretty scary, pituitary tumors are non-cancerous and benign tumors that affect your pituitary gland – the area that produces the hormones FSH and LH around ovulation. These benign tumors can cause irregular periods and missed periods in pre-menopausal women.
The tumors are called prolactinomas, and they cause your pituitary gland to produce higher than normal levels of the hormone prolactin (the hormone that stimulates your breast milk production). Yes, non-pregnant women still produce prolactin and men do too. Scientists don’t know why, but everyone does produce this hormone.
High levels of prolactin in your blood can interfere with your ovary function and cause you to have a lower level of estrogen in your body. As a result, it’s common for you to have missed periods, irregular periods, and infertility. You may also produce breast milk, though you’re not breastfeeding.
If you have a prolactinoma, you may also start to experience menopausal symptoms, like hot flashes.
Eating disorders are life-threatening, dangerous conditions that can affect not only your menstrual cycles, but also your overall health. Whether you have anorexia nervosa, and you are starving yourself because you think you are too “fat,” or you have bulimia nervosa, where you are vomiting to lose weight, you should know that this has disastrous effects on your reproductive health.
When you have excessively low body weight (i.e. you’re way too skinny), this can interfere with hormonal functions, which might stop ovulation. These abnormal hormonal changes are the reason that anorexics and bulimics often stop having periods.
When you’re too thin (due to anorexia or excessive weight loss), you don’t have enough fat cells in your body to produce enough estrogen for healthy ovulation. You don’t ovulate, and you will either have a missed period or irregular periods. (Or no periods at all).
Remember that your body needs a certain number of fat cells in order for ovulation and menstruation to take place. When you are way too skinny and have a very low body weight, because of anorexia, everything in your body slows down. Your reproductive organs will shut down, and you will not ovulate and you will not have your periods.
Women who participate in activities and sports that require them to undergo rigorous training often experience skipped periods or no periods at all. The high energy expenditure, stress, and low body fat can contribute to no ovulation and missed periods.
There are some medications that can disrupt menstrual cycles. For example, some chemotherapy drugs, anti-depressants, anti-psychotics, and oral corticosteroids can cause you to have missed periods, or no menstrual periods at all.
As you read under “Stress and Anxiety,” your menstrual cycle is dependent on a fine orchestra of hormones. More specifically, it requires the hypothalamic-pituitary-ovarian axis to be functioning correctly. The hypothalamus in the brain produces gonadotrophin-releasing hormone, which send a message to the pituitary gland. The pituitary gland produces the most important hormones crucial to ovulation and your menstrual period – luteinizing hormone (LH) and the follicle-stimulating (FSH). In response to LH and FSH, the ovaries produce estrogen. All work together in a beautiful symphony to create ovulation and your period every month.
If anything goes wrong in this orchestra of hormones, and you have a hormonal imbalance, it will screw up your menstrual cycle. For example, if there isn’t a LH surge to help that mature egg erupt from the follicle, you will not ovulate and you will have a missed period that month. Similarly, you might have too much estrogen in your body, and this can also cause you to miss your period.
The common hormonal problem that causes missed periods is polycystic ovary syndrome (PCOS). It has been mentioned numerous times in this article, because it is one of the most common reasons for missed periods. With PCOS, your body produces high levels of estrogen and the male hormone, androgen (yes, women produce this hormone too). Missed periods are quite common with PCOS.
Perimenopause, in detail below, is also an example of a hormonal imbalance that can lead to missed periods.
Perimenopause & Early Menopause
Menopause is a normal event in every woman’s life and usually takes place sometime between age 45 and 55. When you hit menopause, this is considered the end of your reproductive life. You stop having periods, and you are no longer able to have children. Menopause is a gradual evolution – you don’t stop having periods overnight. It starts with perimenopause (also called menopause transition), which takes place a couple of years before you hit full-blown menopause.
For some women, their menopausal transition is only two or three years; others may go through perimenopause for ten years. The average length of menopausal transition is about four years, but this can vary. There is no exact time period for perimenopause and no official “start” and “stop” of perimenopause. Often it is even hard for doctors to tell whether or not you’re in your transition (unless they do extensive testing, and even with testing your hormones in your blood, you may not get a concrete answer).
Because your ovaries start to produce less estrogen during perimenopause, it is common to have irregular periods and you may also start to experience common menopausal symptoms – such as hot flashes and decreased sex drive. Your PMS symptoms may also get worse.
Perimenopause can cause your periods to become very wonky. Your cycle can change dramatically. You may have really heavy periods one month, and a lighter period the next. It is also common for your periods to get closer together. Missing your period is also common with perimenopause.
However, never assume that your missed period is related to perimenopause if you’re in your 40s. You can still get pregnant during this time, so take a home pregnancy test just to be sure.
If you are under age 40 and you are starting to miss your period, or your menstrual cycle is becoming irregular, early menopause might be to blame in some cases.
Early menopause – or menopause that occurs before you reach 40 years old – may be the result of certain medical treatments, such as a hysterectomy or bilateral oophorectomy (when both your ovaries are removed), or it can just occur on its own. When early menopause just happens, doctors diagnose you with a condition called primary ovarian insufficiency (also known as premature ovarian failure).
With primary ovarian insufficiency, your ovaries either stop releasing eggs (you stop having periods), or they release them intermittently; not on a regular basis (you’ll have missed periods and irregular menstrual cycles). You will have a period when an egg is released and you ovulate, but on the months that your ovaries don’t release any eggs, you will miss your period.
With early menopause, your body either stops producing the hormones needed for menstruation – such as estrogen and progesterone, or it only produces it intermittently on the months that an egg is released.
Because of these ovarian problems, it can be hard for you to conceive when you are in early menopause. It’s not impossible, but it is harder to conceive, because you just never know when you are ovulating. Only 5 to 10 percent of women with primary ovarian insufficiency are able to conceive normally. Other women have to go through in vitro fertilization using donor eggs in order to get pregnant.
Problems with your thyroid
– Hypothyroidism (underactive thyroid) can cause you to have missed periods and other menstrual irregularities. Thyroid disorders can alter the production of the hormone prolactin. This affects your hypothalamus and disrupts your regular menstrual cycle.
– If your uterus is scarred from disease or medical procedures, this can prevent the normal buildup and shedding of the uterine lining common to a regular menstrual cycle. As a result, you may have very light periods, or no menstrual periods at all. Your uterus can become scarred during a cesarean section, D & C procedure, treatment for uterine fibroids, or due to a health complication.
Traveling and Jetlag
– Traveling and jet lag can easily throw the most predictable 28-day cycle into an unpredictable one. Traveling is a lot of fun, but it can also come with a crazy ton of stress. From the frenzy of preparing for your trip to actually traveling, knowing exactly where to go and what to do on each day of your travels, this stress level can have a crazy influence on your menstrual cycle.
Not to mention, when you are traveling, you don’t have the same eating habits. If you are normally nutritionally conscious, that can go out the window as you indulge in the culinary fare of the area you’re in.
Your exercise and physical activity level also changes. If you work out regularly, you may not have time for this when you are traveling. And if you are usually a sloth at home, your travels may cause you to increase your exercise levels, and this rapid lifestyle change (albeit it’s temporary) can affect your periods.
Traveling also comes with jet lag. New sleep schedules can great affect your circadian rhythm, which affects your body’s regular systems. In fact, did you know that studies have shown that many flight attendants (who travel all the time) experience irregular menstrual cycles (late and missed periods) due to jet lag and their circadian rhythms being off?
How to Cope When You Miss a Period
If you have missed your period, but you’re only a week late, try not to stress out. There’s a possibility that your period is just late. Obviously, you should take a home pregnancy test (or two or three) to ensure that you’re not pregnant.
Contact your healthcare provider and make an appointment to see your doctor. You may be asked to undergo a variety of tests and examines to pinpoint why you’ve missed your period.
Your treatment will depend on what’s causing you to miss your menstrual period. Your doctor may prescribe medication to help treat you, or he may recommend that you make certain lifestyle changes.
The bottom line is – don’t stress out if you have a missed period. Some women miss their periods now and then. Chances are your period will return next month.
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