Do I get period while continuing meprate

I got period on 27th of may. Every month I used to get pre menstrual cramps 1 week to 10 days prior getting period. In June I didn't get any premenstrual cramps. Then I spotted on 28th of june and thought I got period. But after sometime it stopped. After that every day I bleed lightly. Since 10 days bleeding increased but not like regular periods. I have hypo thyroidsm since 10 years and is under medication for the same. When I was 18, same happened but then early i consulted gynic and used 3 month coarse of progesterone. I experience this kind of spotting for few days before period once or twice a year. But this time it is different. So I consulted gynic on online. She told to use meprate 10mg once per day for five days. It is 3rd day and I am getting premenstrual cramps. Should I use meprate for only 5 days or 21 days?? If so will I get period while using the tablet? I am not married and not been in relationship upto now.