How Soon After Your Period Can You Get Pregnant? Sperm can live inside your uterus for up to 5 days after having sex, and pregnancy can only happen if there is sperm in your uterus or fallopian tubes when you ovulate.
For many people, ovulation occurs around day 14 of your cycle. However, having sex without a condom or another barrier method during your period or outside your expected fertile window does not guarantee that you will not become pregnant.
For people with shorter cycles – the average is 28 to 30 days – pregnancy can still occur if you have sex during your period. For example, if you have sex near the end of your period and you ovulate early, you could get pregnant. Usually the best way to prevent pregnancy is to use birth control, condoms, or another barrier method.