After having intercourse, taking Eusemide will not play a role in contraception. It is a short-acting contraceptive pill, which is taken orally on the 5th day of menstruation, once a day, one tablet at a time, for twenty-one days, which can prevent pregnancy for one month in clinical practice. The main mechanism of contraception is to inhibit ovulation and change the thickness of the endometrium, so it is not possible to take one tablet to inhibit ovulation and change the thickness of the endometrium, it takes one month to achieve such effect. Therefore, if you want to prevent pregnancy after intercourse, you can take the emergency contraceptive pill orally, which is recommended to be taken within seventy-two hours after intercourse. So it is best to use condoms in your daily life to prevent pregnancy, and there are basically no side effects.