Taking the 72-hour emergency contraceptive pill usually leads to menstruation in 3-7 days. The 72-hour pill refers to the emergency contraceptive pill, which may affect the endocrine function of the ovaries after taking the pill due to its high dose of progestin, resulting in a delayed or early menstrual cycle with withdrawal bleeding 3-7 days after stopping the pill. If menstruation is still late for a week, pregnancy is possible and the patient should undergo a pregnancy test. If irregular vaginal bleeding with abdominal pain occurs, prompt medical attention is needed to rule out ectopic pregnancy. In addition, women should be aware that the emergency contraceptive pill should only be used as a temporary remedial contraceptive method and should not be taken as a regular contraceptive pill, at most once in a month. At the same time, frequent use of this pill can cause menstrual disorders, and in serious cases, infertility.