Women do not do contraception after sex: 1, occurs in the ovulation, if it is in the 72 hours after sex, women can take emergency contraception such as Yutting, contraceptive success rate is generally about 90%. 2, if in the women’s menstrual period just after the clean 4 days or soon to come to the menstrual period within 3-4 days after sex without contraception, this period due to the egg has not been discharged, the women can also be temporarily observed. The woman can observe for the time being. If a woman has a normal sex life and is of childbearing age, it is better to use contraceptive measures such as penile condom or IUD, which are safer and will not adversely affect the woman’s body. Otherwise, if a woman has frequent unwanted pregnancies, it will easily cause thin uterine lining and endocrine disorders, which will have a greater negative impact on the body.