I'm towards the end of this whole miscarriage (hopefully) and last week I passed the embryo. I've been passing clots less and less since, but still bleeding. Today, I passed something else. It was oval shaped, a little hard, and it had a long, string-like substance attached to it along with lots of clots. I broke open the inside and it was all dark blood. Does anyone know what this is?? Should I be concerned?