The emergency contraceptive pill can be taken within 72 hours of intercourse, and the earlier you take it, the better the contraceptive effect. Note that when taking the pill must not eat within 2 hours before and after taking the pill, eating too early will affect the absorption of the drug, affecting the effectiveness of contraception. But the pill is not 100% contraceptive, in time to take the pill, the contraceptive effect in 98%, the chances are relatively high. So if you do not use contraception during intercourse during ovulation, or if you fail to use contraception, you can take emergency contraceptive pills to remedy the situation, commonly used emergency contraceptive pills are Yutin and gold Yutin. It is important to note that the pill only plays a contraceptive role for sex before taking the pill, but not for sex after taking the pill.