Normally, withdrawal bleeding does not usually last more than 7 days. Withdrawal bleeding is defined as endometrial bleeding that occurs vaginally after taking oral emergency contraceptives or short-acting contraceptives. The duration and amount of withdrawal bleeding is related to the thickness of the endometrium and the rate of exfoliation. If the endometrium is thicker, the duration of withdrawal bleeding will be longer; if the endometrium is thinner, the duration of withdrawal bleeding will be shorter. However, under normal circumstances, the withdrawal bleeding will not exceed 7 days. In addition, if the withdrawal bleeding exceeds 7 days or if the amount of withdrawal bleeding exceeds the normal amount of menstruation, it is an abnormal condition, and you need to go to the gynecological clinic for relevant examinations, such as ultrasound or sex hormone six tests to clarify the specific cause, and then carry out symptomatic treatment according to the examination results.