Heavy Bleeding Upon Heavy Lifting After Abortion?

I had a medication abortion at almost 8wks initiated on feb 24th. I had a follow up visit later in march that showed all the main parts had aborted successfully, there was some slight shading on the probe ultrasound image but since I was since bleeding lightly they said it was fine. I bled lightly on and off for several weeks. Early april I had some horrible cramps and it felt (what I can best explain) like a football was in me. They lasted for a couple days and then went and I had a normal period afterwards. Bleeding trailed off and stopped in about 10 days (long periods are normal for me). I wasn't worried about nothing. Then yesterday at work after heavy lifting on the morning shift I started to cramp and bleed heavy and passed 2 clots a little smaller than a golf ball. About 2-3hrs after stopping the heavy lifting the bleeding/clotting quit (after the clots quit coming the bleeding quit). Then on the evening shift (i do doubles) after heavy lifting again I started to cramp and bleed heavy. I passed about 4 large clots again. Again, about 2-3hrs after stopping the heavy lifting the bleeding/clotting quit. And the same thing with after the clots quit coming the bleeding quit.

?? Any ideas? I feel perfectly fine. No fever, no discharge, nothing out of the ordinary except for the episodes yesterday. Today I am just bleeding very lightly (just a little on the tissue when I wipe).

Fyi I am 23yrs old and have one child (4yrs) that was born vaginally. No issues except for slight uterine prolapse and a family history of prolapse & hormonal problems occuring at early ages. My mother underwent uterine ablasion (sp?) in early 30's for heavy and long periods and also began to deal with peri-menopause not long after.

Thanks for any input. I am scheduling an appt with my ob/gyn but wanted some opinions/thoughts.