If you had intercourse and the next day started your usual 3-day period can still be pregnant?

Yes, it is still possible to be pregnant even if you started your period the day after intercourse. Although less likely, it is possible to get pregnant just before, during, or just after your period. This can happen if you ovulated (released an egg from one of your ovaries) at a different time than usual, or if you have an unusually short menstrual cycle. Additionally, periods can be irregular for many reasons including hormonal changes, stress, or pregnancy itself, so assuming you are not pregnant based solely on having a period may not be accurate. If you are concerned about pregnancy, it is best to take a pregnancy test to confirm whether or not you are pregnant.