It's unlikely that you'll get pregnant just after your period, although it can happen. Sperm can sometimes survive in the body for up to 5 days after having sex. This means it may be possible to get pregnant soon after your period finishes if you ovulate early, especially if your menstrual cycle is naturally short. Ovulation means that your ovaries release an egg which is ready to be fertilized by male sperm. Your first ovulation occurs around 2 weeks before your first menstruation.