I have a female patient (31 years old) who has had underwent D & C following an incomplete abortion. She was covered with Metronidazole tabs and Amoxicillin caps for 5 days. There after everything was fine except that for the last three months including this month, she has been experiencing unusual menstrual bleeding. The bleed looks dark red scanty for the 1st and 2nd day but becomes a bit bright on the remained two days. Changes pad twice over 24 hours. There is no any h/o of abdominal pains and the bleed is never having an unpleasant/ offensive smell. No h/o painful sexual intercourse. No h/o vaginal itching or dysuria. What could be the problem?