Pregnancy is calculated from the first day of the last menstrual period. 20 days of pregnancy means 20 days of menopause. If you have sex on the day of ovulation and conceive successfully, then the fertilized egg has just been laid and the gestational sac has not yet been formed, and abortion can only be performed if the gestational sac is seen by ultrasound and confirmed to be intrauterine. Therefore, abortion cannot be performed at 20 days of pregnancy. If the so-called 20 days of pregnancy is counted from the time of intercourse, at this time it is about 5 weeks of pregnancy, and if the gestational sac is seen by ultrasound and confirmed to be intrauterine, abortion can be performed. However, a review is needed after the abortion to avoid incomplete abortion and intrauterine residue. After abortion, women should pay attention to increase nutrition, avoid catching cold and flu to promote early recovery of the uterus, and do not eat cold and stimulating food. Keep the vulva clean, and prohibit tub bathing and sexual life for 1 month.