I Havent Had My Period Since The Frist Week Of

I havent had my period since the frist week of june no im not pregnant. So i went to a doctor on the 4th of September and she put me on primolut 3 a day for 10days. i even started on my second script untill i went online and read that people stop after the frist script and have had there period with in a week. All up ive taken 15days worth of primolut stopped taken them for a week now and still no period. Im worried that something is wrong please reply