Hi - I can't say for sure what you tore off, but it could have been a piece of the placenta, or just a blood clot, which is normal to pass those.
This describes the process, if you took the meds they describe -
I don't know how "legal" it was, depending on where you live and how far along you were, which you absolutely don't need to share here. You can google it though, if it's safe for you to do that, given browser histories, who sees your computer/phone, and the like.
If you are close to a Planned Parenthood, they won't worry about legalities. They'll just want to make sure you're okay.
If you're not in any pain, if your bleeding has slowed, just watch for signs of infection. If you get a fever, cramping, nausea or vomiting, then you'll need to seek medical attention.
I'm really sorry you had to do this alone, and have to worry about legalities when you should just be worried about your health. Whatever your reasons for doing this, legalities and fears about them shouldn't be a part of it.
Sending you all kinds of gentle hugs and thoughts for healing.