Can you get pregnant from having sex the day before your period?

Although having sex the day before menstruation is not during a woman's ovulation period, there is still a theoretical possibility of pregnancy. A woman's menstrual cycle is typically around 28 days, with ovulation usually occurring on day 14 of the cycle, although this can vary from person to person. The released egg can survive for 12–24 hours after ovulation, while sperm can survive in the body for 2–5 days. Therefore, if a woman has an irregular or shorter menstrual cycle, ovulation may occur earlier, and having sex the day before menstruation could coincide with ovulation, potentially resulting in pregnancy.

To more accurately avoid unintended pregnancy, contraceptive methods such as condoms, oral contraceptives, or other non-pharmacological contraceptive measures can be used. Additionally, understanding your menstrual cycle and ovulation timing can help plan sexual activity. If you are concerned about pregnancy, you can take a pregnancy test one week after your next expected period, or consult a doctor for further advice.