If you want to postpone the onset of menstruation due to special circumstances, then the short-acting contraceptive pill is most effective when taken orally five days before the menstrual period. In this case, it is necessary to take the pill orally until the end of the special period, and under normal circumstances the period will come within a week after stopping the pill. If you do not take the pill orally in time for the first five days of your period, you can also supplement with progestin during the second half of your period. Progestin supplementation causes no withdrawal bleeding to occur and also achieves the goal of delaying menstruation. However, the effect is relatively unstable and the onset of menstruation may occur during the use of the pill. If there are still a few days before the onset of menstruation and you want to postpone your period at this time, the effect of its administration is the most unstable and you can consider intramuscular progesterone injections. Menstruation has its own pattern, try not to influence the menstrual cycle with medication. If there are special circumstances that require adjustment, plan early and take the oral short-acting contraceptive pill for best results.