Can You Get Pregnant on Your Period?

It's a question we've all probably asked ourselves, and one we thought there was a definite answer to: can you get pregnant on your period? Well, the answer is yes — but it's very unlikely, so hear us out.

First, it's important to understand how the monthly cycle works. Menstruation is in essence the shedding of the endometrium, which is the inner lining of the uterus. On the first day of your period, hormone levels drop and menstrual blood flows from the uterus through the small opening in the cervix, shedding the tissue lining. Around day 14 of the monthly menstrual cycle, hormones cause a mature follicle in the ovaries to burst, then release an egg from the ovary (ovulation). The egg travels down the fallopian tube toward the uterus — a sperm can unite with an egg here, fertilizing it. However, if the egg is not fertilized, the egg breaks apart and is shed during the period, which occurs back around day one of the cycle.

The odds of getting pregnant during your period are extremely low, but it can (and has) happened. As Anate Brauer, MD, FACOG, an NY-based double board-certified reproductive endocrinologist and ob-gyn at RMA of New York, explains, "While it's unlikely to conceive while your uterus is still shedding (what we refer to as menstrual blood), it's not impossible. It all has to do with when in your cycle you ovulate. Ovulation typically occurs on the 14th day of an average menstrual cycle and lasts for 12 to 24 hours; however, not every person ovulates at the same time in their cycle. While one person may ovulate on day 14, someone else may ovulate as early as day 6 or 7 or even as late as day 20."

Dr. Brauer adds that sperm can live inside of you for up to five days after it is released, so if you have sex toward the end of your period, it would hypothetically be possible to conceive four or five days later with your early ovulation. "This means that if you have sex toward the end of your period, sperm can still hang around long enough to fertilize an egg that is released days after your period ends," she says.

Ultimately, Dr. Brauer says, "While it's not impossible to get pregnant while on your period, your chances are pretty slim."

As mentioned above, the time after your period is when preovulation and ovulation begins and hormones increase. This means you are most fertile between day 11 and day 21 (approximately) of your menstrual cycle, according to the American Pregnancy Association. So having unprotected sex during this time significantly increases your chance of getting pregnant. The period of ovulation is the prime time for conception.

However, the probability for conceiving for the time right before your period is "extremely low" for women who have a 28- to 30-day or longer cycle. "If you know when ovulation occurred and you wait for 36 to 48 hours later, then you should be beyond the possibilities of conception," says the American Pregnancy Association. The egg is only available for about 12 to 24 hours for conception after ovulation occurs. Once the egg has been released, progesterone starts to rise, which is a signal to your ovaries they they don't need to release any more eggs this month. "Your cervical mucus will dry up and create a plug to prevent any additional sperm from entering the uterus," Parents reports.

So the short answer is yes, there is a possibility of getting pregnant during your period, albeit a very low chance of it. Because every woman's body and therefore cycle is very different, the chances of conceiving can differ too.

— Additional reporting by Lena Felton

Hilary White is the former PS living editor.

Lena Felton is the senior director of features and special content at POPSUGAR, where she oversees feature stories, special projects, and our identity content. Previously, she was an editor at The Washington Post, where she led a team covering issues of gender and identity.