The amount of withdrawal bleeding is relatively large, usually not pregnant, but only withdrawal bleeding can not be determined, should be combined with other related examinations. There are two types of withdrawal bleeding, one is the withdrawal bleeding after taking emergency contraceptive pills, and the other is the withdrawal bleeding produced by taking progestin drugs to regulate menstruation. 1. Retreating bleeding caused by emergency contraceptive pills: Emergency contraceptive pills belong to the high progestin drugs, which produce retreating bleeding and menstrual flow is basically the same, and this situation usually excludes the possibility of pregnancy. 2. Taking progesterone to regulate menstruation: generally take progesterone drugs for about 3 to 5 days, 3 to 7 days after stopping the drug will produce retreating bleeding, which is a method of regulating menstruation, with the retreating bleeding is relatively large, the possibility of pregnancy is ruled out. If you need to confirm whether you are pregnant or not, you need to go to the hospital for relevant examinations, and you can’t tell the exact amount of withdrawal bleeding alone.