There is no absolute safety period, only relative safety period. Generally speaking, 8 days after menstruation is clean is a safe period, but this method of contraception is not desirable, and there are few cases of unintended pregnancy. Normal ovulation is about two weeks before each menstrual period, sperm can survive in the body for three days, and ovulation is not fixed, it may be due to sexual stimulation, the environment and other factors affecting the ovulation time, so ovulation is irregularly early or backward, if you follow the so-called safe period contraception, the probability of pregnancy is relatively large, especially for women with irregular menstruation is not recommended this method. Contraception. The actual emergency contraceptive pill is an emergency remedy after the failure to do so, and you can actually wear a condom, but of course, if you don’t wear a condom throughout, it’s not absolutely safe, and there is a small amount of sperm in the prostate fluid that can form a fertilized egg in the case of ovulation. The relatively reliable contraceptive methods are intrauterine device and tubal ligation as well as oral short-acting contraceptive pills, compared to the fact that it is more practical for fertile women to wear a condom, and it is more practical for fertile women to wear an IUD. If a woman has been dissected two or three times, she can undergo intraoperative tubal ligation. If you don’t want to get pregnant, it is recommended not to take the so-called safe period contraception, which is likely to occur accidental pregnancy.