Short-acting oral contraceptives are usually taken before going to bed, and if you are taking them for contraception, you should start taking them on the 1st day of your period, and you should also use contraception for up to 1 week after your 1st dose, and no longer need to use contraception after 1 week. Usually, it is taken for 21 days in 1 month, and menstruation will come in 3-7 days after stopping the medicine. If applied continuously, you can start taking it on the 5th day of your period. As long as the short-acting oral contraceptive pill is not missed, the success rate of contraception can reach more than 99%; if there is a leakage of the phenomenon, in the second day must make up for the time that should be taken by mouth or need to be taken by mouth again; if the leakage of more than 2 days, then do not continue to take by mouth, wait for the occurrence of vaginal bleeding, that is, the withdrawal of bleeding on the fifth day after the beginning of the pill, but at this time must pay attention to contraception, because there is a risk of pregnancy, the pill can be used to prevent pregnancy. But at this time, you must pay attention to contraception, because there is a possibility of pregnancy if there is a missed dose.