Here’s what you need to know about your chances of getting pregnant if you are having period sex.

How does conception occur?

The ability to conceive is miraculous. It requires the meeting of a male’s sperm with a female’s egg at just the right time, and the egg allowing the sperm to join with it. Once a woman ovulates (when her ovary releases an egg (ovum)), the ovum is viable for 12 and 24 hours. The male’s sperm can live inside a woman’s body for about 5 days.

The typical female cycle is 28 days. Day 1 is when she starts her period, and ovulation would typically occur around day 14 of her cycle. Ovulation can vary based on a woman’s cycle length. Some women have a longer cycle of around 35 days between periods. Ovulation would then happen around day 21. Women with a shorter cycle of 21 days would ovulate around day 7.

If a sperm is available in the uterus or fallopian tubes when a viable ovum is present, fertilisation and pregnancy can occur.

How can a woman get pregnant on her period?

Knowing that you will ovulate several days after your period, and that a man’s sperm can live inside a woman’s body for 5 days, it is quite possible that you can fall pregnant if you have sex toward the end of your period.

If you have a 28 day cycle, and have unprotected sex on day 7 (even if still on your period), sperm can stay alive in your body until day 12. While you may usually ovulate on day 14, you can also ovulate on day 12, 13, or 14 in a 28 day cycle. This means that sperm and a viable egg could meet and fertilisation could occur.

Women with a shorter cycle would have less time between having their periods and ovulating, and therefore have a higher risk of pregnancy.

What are the chances a woman can get pregnant on her period?

A woman’s likelihood of getting pregnant can rise and fall throughout her ovulation cycle. While the average female’s monthly cycle may be 29 days, others may have a cycle that varies from 20 to 40 days, or longer.

The likelihood that a woman will get pregnant one to two days after she starts bleeding is nearly zero (but not absolutely zero). But the likelihood starts to increase again with each successive day closer to ovulation, even though she’s still bleeding.

Birth control precautions

If you’re trying to get pregnant, having sex on your period won’t likely help you to conceive unless your menstrual cycle is less than 28 days. But it’s always possible that you could become pregnant as long as there is sperm waiting in the fallopian tubes for a newly released ovum

If you’re not trying to become pregnant, it’s important to have protected sex every time. This includes using some form of contraception like wearing a condom or taking birth control pills.

Birth control pills will not provide a barrier against sexually transmitted diseases like herpes, gonorrhoea, or chlamydia. To protect yourself from unwanted infections, have your partner wear a condom.

Final Word

A woman’s ovulation cycles can vary, so it’s statistically possible you could become pregnant while on your period. While pregnancy is less likely in the earlier days of your period, the chances increase in the later days.

If you are not familiar with your cycle, or don’t have a regular cycle it’s easy to mistake vaginal bleeding for the beginning of a period. It’s possible you could bleed during ovulation when you’re most fertile. This could easily be mistaken for a period. Having unprotected sex at this time dramatically increases your chances of becoming pregnant.