If the menstrual period is clean, the 2nd day can have sex, but must pay attention to the hygiene before and after sex, both husband and wife should be cleaned, to avoid pathogenic bacteria infection and cause inflammation of the reproductive tract. If the menstrual period is relatively long, such as 9 days to clean, the menstrual cycle is relatively short, may also be clean on the 2nd day just to catch up with ovulation, this time to have sex, it is recommended that if there is no plan to get pregnant, it is best to take contraception, it is recommended that the best in the process of the whole process of sexual intercourse with a condom to give contraception. If the menstruation is clean for 5 days and the menstrual cycle is 28-30 days, the chance of getting pregnant is also very small if you do not take contraceptive measures. It is recommended to clinically grasp the time of your own ovulation, and then have intercourse to avoid the possibility of pregnancy.