Oral short-acting contraceptives can prevent pregnancy for 1 month. The most commonly used clinically are Eusemide and Mafron, both of which can be used for 1 month of contraception. They are taken orally starting on the 5th day of menstruation and are taken once a day, one tablet for 21 consecutive days. The mechanism of contraception is to inhibit ovulation and change the thickness of the endometrium to achieve the purpose of contraception. In the process of taking oral contraceptives, it is especially important not to miss a dose, and in case of missing a dose, it is recommended to take it immediately within 12 hours to achieve a more satisfactory effect. However, no drug and no contraceptive method is 100%, the contraceptive pill is only 98% effective, so there is a possibility of pregnancy.