Prolonged period. Reason behind this?

On Feb 4 my period was skipped, then March 4 I got my period on April 4 my period didn't happen but due to exercises on 26th April I got my period. On 26 and 27 , the bleeding was too light. On 28th (3rd day) I did exercise for 45 mints. Constantly and then my flow started. On 29, 30 April and 1st May I got medium to 2-3 big clots. On 8th day of my period (2nd May) there was no period. I went to Dr. For checkups as planning for conceiving. I did exercises and again the flow started till 6th May. The bleeding stops in day but I get it at night or my periods are little heavy at day time and no bleeding or light bleeding at night. On 6th May that is 11th day of my period i got checked my endometrium thickness and the ultrasound report was 10mm. Ovaries are normal as well as uterus. Small follicles developed.The Dr. Gave me trenexa tablets for 3 days to consume still the bleeding is not stopped rather I get small clots at times. I am based in baripada. What could be the reason behind this?