Is Vaginal Bleeding Common After Miscarriage?

I have a miscarriagelast june 5 because i have a polyp in my uterus so i underwent D&C after finding that the baby has no cardiac beat. I asked my doctor if ever the polyp had been removed already but she told me that she is not 100 percent sure due to many tissues in my uterus. Last july 3 i experienced a vaginal bleeding after i urinate.Sometimes mucous or fibroid like tissues accompanies in the blood after urinating.Up to this time i am experiencing vaginal bleeding and only noticed that this day the bleeding is too heavy. Is this natural for women having miscarriage or is it because there is still the presence of polyp in my uterus? please advice me doc.thank you!!