علت ادامه داشتن خونریزی بعد از زایمان

سلام خسته نباشید سونو داخلی انجام دادم می خواستم ببینم جوابش چی هست بعد از پنجاه از زایمان روز هنوز خون ریزی دارم Uteru is normal in size with normal parenchymal echogenicity.(et:14mm)
Heterogeneous structure measuring 23*18 mm is seen in endometrial cavity with vascularity in some parts, suggestive for retained tissue and adherent clot

Both ovaries are normal in size and echo with no solid whit no solid or cystic lesion.
No free fluid is pelvic cavity