No, you don’t get a free pass this week, because life isn’t fair. It’s very unlikely to get pregnant while on your period, but it’s possible, Mary Jane Minkin, MD, clinical professor of obstetrics, gynecology, and reproductive sciences at Yale School of Medicine told BuzzFeed Life. Here’s why: Sperm can live inside you for up to seven days (WHAT). For most women, ovulation occurs around 14 days from the start of your last period, but this can sometimes happen earlier. If that’s the case and there are still sperm alive and thriving in there, they can meet and make a baby.