
In this article
Can you get pregnant when on your period? This is a common question. In fact, it’s a common misconception that you can’t. The reality is that women are less likely to get pregnant on their period, but they really can. Menstruation marks the point of the menstrual cycle where the egg that hasn’t been fertilized by sperm is sloughed off and discharged with blood. It is still possible to fertilize an egg during your period but it might not be the one being discharged.
Let's take a deeper look at exactly what happens during your period and how it is possible to get pregnant while on it.
Had a full period but am pregnant: How did this happen?

Getting pregnant while on your period has more to do with the timing of having sperm introduced into the vagina and when you ovulate. “Once your egg is released, it only has 24 hours to get fertilized. However, sperm can stay alive in the genital tract for five days,” Dr. Sarah Tedjasukmana of Sydney Perinatal Doctors told Mom.com.
What that means is that you aren’t getting pregnant based on the unfertilized egg that is being discharged with the blood. You are getting pregnant because you started ovulating shortly after sex and the sperm was still viable in your system.
Dr. Tedjasukmana also told Mom.com that not all bleeding is a period, which is important to understand. “Some women have blood with ovulation! Some women may experience a bleed at a different time of the month for reasons such as infection or cervical abnormalities,” he said.
This means that you aren’t discharging an unfertilized egg during some bleeding as you do during menstruation. So while it seems as if you got pregnant during your period, you really didn't. But you did get pregnant while bleeding.
That is what happened to mom Aleesha Dane, who got pregnant during period sex. “I found out after the fact that you can get pregnant while on your period. For me, it was a false period where I was bleeding but also ovulating,” she told Mom.com.
Women should track their period to truly understand what is a period and what are other types of bleeding. This is important not just to determine if your pregnant, but to help identify other issues such as infections.
How likely is it to get pregnant on your period?

While it does happen, doctors agree that it is not likely that you’ll get pregnant while on your period. The reason is that the ovulation will need to be early. “The textbook cycle is 28 days, with bleeding starting on day one and ovulation occurring on day 14,” Dr. Tedjasukmana continued. For you to get pregnant, something would have to be different in this cycle. A period will last, in most cases, two to eight days.
If you had sex on day eight and sperm could survive in your system for five days, you still would only be 12 days into the cycle. Women who have shorter cycles are more likely to get pregnant from having sex during their period because there is less time between the end of the period and ovulation. Those who have regular periods have the lowest chance of getting pregnant during their period simply because there isn’t enough time for ovulation to start.
But if you have a short cycle, it is possible to be inseminated and that the semen will remain viable for the days after sex. If you cycle early, this can lead to pregnancy.
Birth control precautions

Because there is no guarantee that you can’t get pregnant while on your period, you may still want to use birth control. Birth control will still be your best method of preventing an unwanted pregnancy. Of course, there are other reasons to use certain birth control, such as a condom, to help protect against sexually transmitted diseases. But using birth control pills and other widely used contraceptives can help protect against an unwanted pregnancy.
Some may decide to try the rhythm method of watching the calendar. Dr. Tedjasukmana says that this is only 76% effective. For those who don’t want to take a contraceptive but want to have the best chance of preventing an unwanted pregnancy, there are more effective natural family planning methods. These include Billings, Creighton, and Marquette methods that track cervical mucus levels. The Marquette Method also tracks estrogen levels and luteinizing hormone levels. Dr. Tedjasukmana says that these methods, when done correctly, can be “99% effective in preventing pregnancy.” Using birth control correctly will always be an important step in preventing unwanted pregnancies. As we can see, just choosing to have sex during your period is not enough to prevent fertilization.
*Disclaimer: The advice on Mom.com is not a substitute for consultation with a medical professional or treatment for a specific condition. You should not use this information to diagnose or treat a health problem without consulting a qualified professional. Please contact your health-care provider with questions and concerns.