It is possible to get pregnant if you have intercourse 3 days after your period is clean. If a woman has a very regular period, ovulation usually occurs about 14 days before the next period. If a woman’s ovulation is affected by mood swings, mental tension, environmental changes, or stressful work, life, or study, there is a possibility that ovulation may occur before or after ovulation, in which case, it is possible for a woman to become pregnant if she has intercourse 3 days after her period is clean. Therefore, once a woman has delayed menstruation, she needs to be alert and go to the hospital as soon as possible to check the blood HCG value to exclude the delayed menstruation caused by pregnancy, there is no contraceptive measure that is foolproof.