Talk to Gynecologist on Irregular Periods After Miscarriage

Aoa dear drs. I had miscarriage in feb bleeding continued for 10 days then stopped. Miscarriage was all natural I didn’t used any tablets or dnc. After 43 days I had my 1st period on 14 April which continued for 13 days then stopped. Then again my 2nd cycle started on 18 may and today is 4 June there is still slight pinkish spotting. I did my ultrasound all was clear. Pregnancy blood test was negative. What’s the reason of this spotting. Is this normal to have such longer periods after miscarriage. Do I need to take any medication? Dr gave me duphaston and said if u can wait for periods to stop normally then okay otherwise take duphaston. What should I do? I’m really confused. I have no other medical problem