Talk to Gynecologist on Pp Bleeding

I had postpartum bleeding till almost three months on and off. Dr did my dnc and took out some tissue. Acc to reports it's chronic non specific demetritis. Now after almost 19 days of dnc, I'm experiencing really heavy bleeding like periods. Dr advised me to take contraceptive pills but I'm breastfeeding so she gave me 2 ponstan thrice a day for 5 days to lessen the flow. Is it ok to take it in such a large amount? What do you suggest? I need a second opinion please because my little one is only 3.5 months old and exclusively breastfed