When you can get pregnant on your period
If you happen to ovulate early during a brief cycle, you could become pregnant while having your period. For instance, a woman with a 24-day cycle could ovulate as early as day seven. Therefore, if you have sex during that period and your period lasts the entire week, ending on day seven, you may become pregnant.
The likelihood of ovulating close to your period is low, but not impossible. A 2013 study in Human Reproduction estimated the date of conception for 5,830 pregnancies. More than half, about 58%, of people conceived around day 12 or 13 of their cycle. However, 2% of participants were within their fertility window on day four, which would almost certainly overlap with their period.
Moreover, the length of a cycle is extremely broad. For example, a review, published in 2019 in Digital Medicine, analyzed more than 81,600 cycles and found that only 13% were 28 days long Some lasted up to 50 days, while others lasted only 15 days.
Factors that change the time you ovulate
The length of a menstrual cycle is largely influenced by the sex hormones progesterone and estrogen. For instance, during a cycle, increasing estrogen levels cause ovulation and thicken the uterine lining, enabling you to conceive and raise a fertilized egg.
Changes in cycle length and when you ovulate can result from minor variations in estrogen and progesterone levels. Age, ethnicity, and body mass index are some of the variables that can cause these changes.
When you ovulate and the length of your cycle can both be affected by stress, illness, and other medical conditions. Childson explains that a person with a 31-day cycle “might have a shorter cycle than their average and have a slip-up.”
Can You Get Pregnant if You Have Sex During Your Period?
Most likely, having sex while on your period won’t result in pregnancy. Your ovulation time is several days away, which reduces your chances of becoming pregnant at this time. However, there are exceptions. Women whose cycles typically last 28 to 30 days or longer are affected by this. You are ovulating earlier in the cycle if your cycle is shorter, say every 21 to 24 days. You could have sex at the end of your period and become pregnant 4 or 5 days later thanks to your early ovulation because sperm can live inside you for up to 5 days.
Although it’s unlikely, getting pregnant during your period is still possible. If you’re trying to get pregnant, now is not the time to have sex.