The contraceptive pill produces a contraceptive effect during its application, so that the patient cannot ovulate, and in this case there is no pregnancy. However, immediately after the pill is discontinued, the ovaries resume ovulation and pregnancy is immediately possible, so the pill does not cause non-pregnancy after it is discontinued, and the pill has a contraceptive effect during its application. In the case of contraceptive pill application, it is usually necessary to follow up whether there is a history of smoking, and contraceptive pills are not recommended for patients who have smoked. Patients taking the pill should also be asked if they have a history of blood clots, and patients with a history of blood clots are not advised to take the pill. Contraceptive pills are also recommended for patients with a high body mass index, which is particularly likely to cause blood clots.