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.
So can you get pregnant during your period?
The odds of getting pregnant during your period are extremely low, but it can (and has) happened. During your period, the part of the menstrual cycle when the egg is released and therefore has the potential to unite with a sperm (aka ovulation) is still several days away. But there are exceptions. According to the American Pregnancy Association, "If you happen to be one of the individuals who has a shorter cycle, there is a chance you could get pregnant while having sex during your period."
This means that the time between your period and your ovulation is closer together. 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. "The probabilities of getting pregnant while on your period are low, but the possibilities are there," says the APA.
What about right before or right after your period?
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, says 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," says Parents.
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.