Sorry about your loss. It sounds like it may have been everything that was left passing through. When I had my first m/c I remember how much blood, clots and pain there was. That has always stuck in my mind. I wasn't given a choice of a d&c though..... I would have gladly taken it if it was offered. I was told that when the fetus passed, I would feel period like cramps...yeah right....after having 3 kids I can compare the pain I had with labor!!:)
Anyhow, I hope that the next scan you have shows that everything has passed.