Can Polyps be formed after D&C? How to differentiate a Polyp from RPOC?

I had a recent misscarriage in first trimester on 08/11/2017 D&C was done on that day.Bleeding didn't stop (Not severe) I did a usg on 16/11/2017 it showed Incomplete abortion.The second D&C was needed and done on 17/11/2017 still bleeding didn't stop.Did another USG showed RPOC changed the doctor.New doctor prescribed 10 misoprostol in a single day (Every 4hrs interval).Bleeding started but stopped after couple of days.Then again after 4 days it started.Very similar to menstruation bleeding.We directly came to Apollo Chennai all the tests to rule out Molar pregnancy or any clotting disorders were done including sugar tolerance.The high end USG shows 'Echogenic material measuring 2.1 × 1.2 cms is seen in the lower end of cavity.Retained product of Gestation.Another USG done from CMC Vellore they have told Polyps seen 19mm also SOL seen 10mm.How can a result may differ from others 3 diagnosis.How can a Polyp be formed followed by a D&C. I am bleeding sometimes off and sometimes on.Latest Beta Hcg-1.1.Doctor asked me to another D&C but with Usg guidance.I am afraid of Adhesion due to multiple surgery.The real time B-Mode USG haven't revealed anything about Polyps or SOL.How to differentiate a Polyp from RPOC ? We are looking forward for a Hysteroscopy on 2nd January.