The timing of withdrawal bleeding followed by menstruation is not fixed and varies from person to person depending on the amount of withdrawal bleeding and the usual menstrual cycle. Withdrawal bleeding is mainly a kind of endometrial bleeding that occurs after taking estrogen or short-acting contraceptive pills or emergency contraceptives. Withdrawal bleeding is equivalent to a menstrual period if it occurs at the time when a period is usually due. However, if the withdrawal bleeding itself is small, particularly short, and does not occur during the usual menstrual period, it will normally occur at the time of the usual menstrual period. Retreat bleeding belongs to endometrial exfoliation bleeding, so during the bleeding period you must pay attention to personal hygiene, wash your vulva regularly, change sanitary napkins regularly, keep your vulva clean and avoid inflammation or pathogenic infections.