Q: Why do I need to get my period before clomiphene?
A: 1. To make sure you haven't ovulated recently.
2. To make sure you are not pregnant.
3. To make sure the lining of the uterus is at the right phase for egg implantation. When no bleeding is induced, the endometrium (lining of the uterus) has been growing and been stimulated for 30 or more days by the time you are expected to ovulate and may not be as receptive to egg implantation. But if a menstrual period is being induced, then the endometrial lining will have about 14 days of growth and stimulation at the time of clomiphene-induced ovulation.
When you get medications to induce bleeding it may start anywhere from 2 days to about 2 weeks after finishing the last pill of progestins or birth control pills.