Having a period but being pregnant is just an illusion. In the early stages of pregnancy, some people will experience a small amount of bleeding for the following reasons: 1) the gestational sac is in bed; 2) the uterine meconium is shed due to insufficient hormone levels, and the time coincides with the time of menstruation, mistaking the bleeding for the onset of menstruation. Pay attention to the observation that the amount is less than menstruation and lasts for about a week or so. Once you find abnormal menstruation during pregnancy preparation, promptly check with early pregnancy test paper, and if it appears positive or weakly positive, you need to check blood human chorionic gonadotropin at the hospital, which does not exclude the existence of ectopic pregnancy or pre-miscarriage. Observe closely, recheck blood and ultrasound examination every few days if necessary, pay attention to rest and do not strain during pregnancy, and carry out birth control under doctor’s guidance if necessary for small amount of bleeding to avoid increased bleeding and pre-eclampsia miscarriage.