If the emergency contraceptive pill is taken in the clinic, it can only control the first coitus within 72 hours after oral contraceptive effect, if the next coitus, need to be taken again within 72 hours of oral contraception. However, it is not recommended to take emergency contraceptive pills frequently, because it is likely to cause damage to liver and kidney function, causing endocrine disorders, causing irregular vaginal bleeding or menstrual disorders. If you are taking short-acting contraceptive pills, you start taking them orally on the fifth day of your menstrual period, and take one tablet once a day for 21 days, for one month only. If you want to take the pill the next month, start taking it again on the fifth day of your period, so that it will work again the next month.