The period when the egg is expelled from the ovary is called ovulation. If you do not want to get pregnant during ovulation, then it is essential to choose the right form of contraception. The pill is the most widely used form of contraception in clinical practice. Depending on the composition and the mechanism of action, birth control pills can be divided into long-acting pills, short-acting pills and emergency pills. The choice of the pill depends on the duration of intercourse. If the patient wants to use the pill for a long period of time, then he or she can take the long-acting pill regularly or take the short-acting pill daily for maintenance treatment, in which case the chances of pregnancy are not very high if he or she has intercourse during ovulation. Patients who inadvertently have sexual intercourse without contraception during ovulation have no significant effect when taking oral long-acting or short-acting contraceptives. In this case, patients are advised to use emergency contraceptive pills for emergency contraception. Under normal circumstances, oral contraceptives are effective, but their success rate is not 100%. Especially with the emergency contraceptive pill, even after taking the pill, there are still a small number of women who fail in contraception. In conclusion, the pill is effective during ovulation, but there are cases of contraceptive failure.