What Is The Bloody Tissue Discharge Through Vagina After An Abortion?

Hi, about an hour ago I passed a peice of bloody tissue from my vagina, flat and about an inch and a half long. This also happened about two or three weeks ago. It was not a blood clot. I have givin birth twice and I know this was not a clot, it is definitley tissue. I had an abortion via the abortion pill in january. The bleeding never really stopped. I have had brown spotting everyday since the initial heavy bleeding from the abortion stopped about the beginning of february. I went to the er and also had my follow up in february. Then I was told the brown (old) blood was normal, but it is almost April, is this still normal to be spotting? I am on the pill so I would think the bleeding would have stopped. Now I am experiencing these bloody pieces of tissue. What could this be?