What Are The Side Effects Of Meprate?

i had scanty bleeding during 2 months of regular period and suddenly periods stopped for 45 days and i thought i was pregnant. the test was negative. Then i consulted a gyno and started taking meprate 10 mg daily once since past 15 days(the course given is for 21days). since 10th day of medication, again bleeding started. Please let me know what is my exact problem and should i stop taking meprate?