I am so sorry for your loss, it's a tough thing to have to go through. I don't know how far along you were, but hopefully you won't have to have a D&C, and everything does pass on its own naturally. Good luck at your appointment this afternoon, I know how emotional it will be for you. Hopefully you can start trying after a cycle, and you're back here soon. I do recommend the Miscarriage/Loss board, as it helped me tremendously in the early days.
All my best to you ... You will get through this.