My heart goes out to you. I hope everything works out well for you. I do hope your baby is fine. Until you have your scan the wait I'm sure is intolerable. You must be out of your mind with worry.
With regards to you wondering about your hCG levels. I'm not 100% sure but when I suffered my two miscarriages, (one at 6 weeks, and my second at 12 weeks), I remember I was still showing I was pregnant days after I miscarried. I was told to go back a week later to check my hormone levels as they can take some time to drop.
I hope all is well with your baby. I'll say a prayer for you :-)