I Had A BabyApril And I Had My Periods In

I had a babyApril and I had my periods in June 25th and was expecting my periods on July 25th but it occurred on the Aug 6th and since then it hasn't stopped. I have become weak n tired and have spoken to my doctor who has prescribed me primulot N for 21 days. I'm worried about clots and other side Effects as this is first time I'm having this tab