TMI can someone tell me what this is???

I'm approx 7-8 weeks and having a miscarriage due to what they think is a blighted ovum (they were never able to see anything inside the gestational sac) I just passed this tissue and I'm wondering if it's the sac? It's about 2-2.5 inches long which seems a bit big to be the sac or placenta. And it's also really flat... not round like the sac should be. I don't want to flush it until I know if it's part of the baby or not, I'd like to bury it if it is. Can anyone help me?