The short-acting pill not only provides contraception, but also regulates the endometrium and helps menstruation to come quickly. Short-acting contraceptive pills are effective after 7 days of oral intake, and the contraceptive effect will be about 99%. When taking the pill orally, try to take it regularly and quantitatively, so as not to change the time of taking it, which may cause abnormal bleeding and even adverse reactions, such as headache, dizziness and breast pain. Short-acting contraceptive pills are usually taken orally for 21 days, and can be stopped after 21 days, and menstruation will occur in about 7 days. If you need to take the pill again, you can take it again between the 2nd and 5th day of your menstrual cycle and a new cycle will be formed.