If you take birth control pills and get your period half a month early, this should be an emergency contraceptive, short-acting contraceptives as long as there is no leakage of the phenomenon, there will not be such a situation. Emergency contraceptives will have certain adverse reactions, will cause menstruation advance, delay, including abnormal bleeding, but not so long in advance, that is, half a month’s time, this may not be menstruation, may be abnormal bleeding. Since emergency contraceptive pills are hormonal pills, they can cause endothelial disorganization, which can cause hormonal disorganization, and sometimes that can cause the chance of abnormal bleeding to occur. This situation is recommended to observe, if the bleeding is very small, is possible to first observe 3-5 days, as long as the end, there is no big problem. If more than 7 days, there is still such bleeding, you need to go to the hospital to do ultrasound, check the endocrine hormones, according to the situation to oral anti-inflammatory and hemostatic drugs to stop bleeding. If necessary, you can also take oral short-acting contraceptives to regulate the whole cycle, because some women take emergency contraceptives, can cause menstrual cycle disruption for three months.