What Causes Presence Of Black Specks In Menstrual Flow?

im 28,5'3 ft.i was 1 month pregnant but my boyfriend gave me a pill to to take so the baby would'nt continue,and after 5 hours i was bleeding for 8 days so i have to go the hospital. and i undergo a raspa. after 1 month im having my menstruation but the thing is i have a black dots on my pads. what is it?