Short-acting contraceptives are combined estrogen and progestogen drugs and are only 99% effective after seven days of oral administration. If you want to have intercourse within seven days before taking the pill, you need to use condoms to avoid the possibility of unintended pregnancy. Although ovulation is in the middle of the cycle, it can be altered by each person’s environment, stress and mental factors. If you are not planning to have a baby, take measures if possible to avoid unwanted pregnancy if you have intercourse within these seven days. After seven days, contraceptive measures are not necessary because the effectiveness of contraception is very high. Short-acting contraceptive pills are recommended to be taken orally for a maximum of three months to six months if you want to achieve the purpose of contraception, so as not to cause thinning of the endometrium or induce other diseases over a long period of time.