The main reason is that it is a short-acting contraceptive pill and its main contraceptive effect is to inhibit ovulation, change the thickness of the endometrium, and prevent the fertilized egg from being laid in order to achieve the purpose of contraception, but due to individual differences, not all people taking TAIE-35 will fully inhibit ovulation, and some may fail in preventing ovulation. In some cases, the ovaries may fail to stop ovulation and pregnancy may occur. If you do not have a period while taking TAIE-35, you should first rule out the possibility of pregnancy. It is recommended to have an ultrasound examination to rule out the possibility of fibroids.