I am not getting my periods for over a year, so my gynac advised  to take Duoluton l for 21 days for 3 months and i used to get periods on 7th day once i complete the course. After 3 months problem still persists, no periods. So i took Duoluton l but intead of 21 days i took for 2 tablets in a day for10 days (2tab X 10days) and completed the course. But now 7th day passed and still no signs of periods. Did pregnancy test too, its negative. Please suggest why this happened and what to do now. Pleaseeee help.