Ovulation and periods go together. You cannot have one without the other. Although it’s a common misconception that you can ovulate without having a period, this isn’t true – unless you are pregnant.
And unless you’re pregnant, you also cannot have a true period without ovulating earlier that month. Technically speaking, you can still experience monthly bleeding without ovulating, but this bleeding is a result of an anovulatory cycle (which means you didn’t ovulate that month) and it’s not considered an actual menstrual period.
Confused? Let me explain. To answer this question, you have to understand how ovulation and menstrual periods work together.
Ovulation and a True Period
For the healthy woman who is not using hormonal birth control, she will ovulate on day 14 of her menstrual cycle. (This is assuming that she has the classic 28-day cycle.) During ovulation, her ovaries will release one mature egg, ready for fertilization. After the egg is released, it stays alive for 12 to 24 hours. If it’s not fertilized by a sperm, it will disintegrate and absorbed into the lining of the uterus (called the endometrium).
Immediately afterwards, the corpus luteum (the follicle that the egg burst out of during ovulation) will begin to produce the hormone progesterone, which significantly thickens the uterine lining in order to receive the fertilized egg. The corpus luteum produces progesterone for roughly 14 days after ovulation. If no egg is fertilized, the uterine lining will begin to break down and slough off.
Two weeks after ovulation, the uterine lining will be discharged through the vagina, and it’s known as your menstrual period. This is a true period. The menstrual bleeding that you experience is a combination of cervical mucus, the uterine lining, and varying amounts of blood.
Ovulation with No Period is Rare
Because your menstrual period is the result of what happens during ovulation, you simply cannot ovulate without a period. The only situations in which you’ve ovulated but had no period are pregnancy and uterine scarring.
When your uterus has been scarred – as a result of a reproductive disease, a C-section, D&C procedure, or another medical procedure – the normal thickening and buildup of the uterine lining (which should happen after ovulation) doesn’t occur. If this is the case, you may ovulate but have no period. (In some cases, you may have a very light period.)
When Do Women Ovulate?
For all women with healthy reproductive systems (who have regular periods), they will ovulate 14 days (2 weeks) before the start of their menstrual period.
So, that’s why women with the average 28-day menstrual cycle, a woman will ovulate on day 14 (two weeks after the first day of her last period). If you have a longer menstrual cycle, for example 35 days between periods, you will ovulate on day 21 of your cycle. (35 minus 14 = 21). And if you have a shorter cycle, for example 21-day menstrual cycles, you will ovulate on day 7 (immediately following your period.)
However, you should keep in mind that there are many factors that can affect the timing of your ovulation – such as stress, illness, certain medications, jetlag, disruption of your regular routines, and other things. Because of these external factors, ovulation doesn’t always occur when it should. It can arrive earlier than expected; or later than normal.
Because the timing of your ovulation can fluctuate, it’s very important that you pay attention to the signs of ovulation – including cervical mucus that is slippery, wet and similar to “egg whites.”
Learn more about the Signs and Symptoms of Ovulation.
Anovulatory Cycle and Estrogen Breakthrough Bleeding
So, we understand that ovulation with no period is rare (and impossible in most cases), but can a woman have her period without ovulating that month?
The answer is no.
But a woman who does not ovulate can experience monthly bleeding. This bleeding isn’t the result of the normal shedding of the uterine lining (as with the case of a true period), but it’s the result of estrogen breakthrough bleeding.
With estrogen breakthrough bleeding, you have excess estrogen that causes your endometrium (lining of uterus) to thicken over an extended period of time. But because you have an anovulatory cycle (you didn’t ovulate that month), there is no progesterone to offer structural support to the growing endometrium. As a result, the uterine lining will begin to slough off, and you’ll experience vaginal bleeding. Estrogen breakthrough bleeding can occur at irregular intervals.
If you’re not charting your menstrual cycle, you can easily mistake this breakthrough bleeding as a regular period.
Anovulatory cycles typically affect women in the teen years and during perimenopause (the years leading up to menopause). However, it can also affect women occasionally throughout their reproductive years. When you have estrogen breakthrough bleeding, it’s a result of a hormonal imbalance.