Some patients do not necessarily experience vaginal bleeding when they take the pill. The pill is a kind of progestin, and if patients take it, most of them will have side effects due to the change of hormone secretion in the body, including the adverse reaction of withdrawal bleeding, which is a normal physiological phenomenon. This is a normal physiological phenomenon. However, due to the different physical conditions of each individual, some patients do not experience withdrawal bleeding after taking this drug, so they do not experience vaginal bleeding, which is also normal. Patients are advised to strictly follow the instructions for use of the drug, or under the guidance of a doctor, in order to facilitate the treatment of the disease.