Yosmin is a short-acting contraceptive, in the clinic, often in the fifth day of menstruation began to take oral, 21 consecutive days, eat 1 tablet a day, the vast majority of 3-7 days after stopping the drug will come to menstruation, if it is relatively sensitive to the drug, because the Yosmin is the estrogen-progestin hormone combination, there may be a delay in the menstrual situation. In addition, in the clinic, if the oral YosiMin, although it is the efficacy of contraception, but in the clinic of contraceptive effect can not necessarily reach 100%, so if there is a delay in menstruation, in the clinic may also be caused by pregnancy. In addition, the delay in taking Yosmin is also directly related to the time of taking Yosmin, which is normally started on the 5th day of the period, but some people start taking Yosmin on the 10th day of the period and take it for 21 days in total, which will definitely make the period delayed.