Taking levonorgestrel can provide emergency contraception. Levonorgestrel is a type of emergency contraceptive that can be used to prevent pregnancy after intercourse during ovulation as long as it is taken correctly. Women who have unprotected sex during ovulation have a high chance of getting pregnant. You can take levonorgestrel for emergency contraception, and you need to take it within 72 hours of having sex in order to have a contraceptive effect, and if you take it beyond that time, it won’t work. The principle of levonorgestrel contraception is to inhibit the discharge of egg cells, prevent sperm from passing through the cervix, and prevent the fertilized egg from implanting so as to play a contraceptive effect. It may cause adverse reactions such as dizziness and fatigue, and should not be used by people with significant abnormalities in liver and kidney function and thrombophilia, and is recommended to be used under the guidance of a doctor.