The normal menstrual cycle is around 21-35 days. 20 days early menstruation is not normal and should be considered as a result of ovarian endocrine dysfunction, abnormal uterine bleeding or even cervical causes. Therefore, it is necessary to go to the gynecology department of the hospital during the bleeding period. It is necessary to check the thickness of the endometrium and the uterine cavity for abnormal growths with ultrasound, and also to do internal gynecological examination to see if there are bleeding spots on the cervix and vaginal wall. If a woman has vaginal bleeding after taking the emergency contraceptive pill, it should be considered as withdrawal bleeding caused by the emergency contraceptive pill and not a real early menstruation.