If you have sex without contraception on the first night and take the emergency contraceptive pill the next day, you can effectively prevent pregnancy. Within 72 hours after sex, oral emergency contraceptive pills, contraceptive success rate is very high, the earlier the oral time the better the effect. However, it should be noted that emergency contraceptive pills cannot be used as a regular contraceptive means of contraception, the side effects are large, only suitable for emergency use. Although the emergency contraceptive pill has a lot of side effects, but unexpected pregnancy is more harmful to women, therefore, as long as there is no preparation for pregnancy, do not hesitate to consume it as soon as possible. You should still stick to condoms, short-acting pills and other means of contraception with fewer side effects on a daily basis.