Period pill

Has someone ever had to take a pill to get your period started? My ob told me to take these pills for 10 days. As soon as my period starts it's day 1, then at 15 days should be my height of ovulation so I need to have sex on day 13, 15 & 17th. And if I don't have another period on day 35 to take a pregnancy test. If it comes up negative then I start the process all over again... For 3 months!!! Has anyone ever had to do this & then turned up pregnant?