Can a girl be pregnant after sex and then getting her period the next day?

It is highly unlikely that a girl can get pregnant after sex and then get her period the next day. The menstrual cycle typically lasts for about 28 days. Ovulation usually occurs around day 14 of the cycle. If the egg is not fertilized, it is shed during menstruation. This process usually begins about two weeks after ovulation. If a girl gets her period the day after sex, it is more likely that she was already in the process of menstruating or has a short luteal phase.