First of all, let me say I am very sorry for what you are going through, but I know exactly how you feel, because the same thing happened to me. I was 7 wks 5 days at my first pre-natal apt (3/6). Same thing, they saw a gestational sac, and no baby. This was my second pregnancy, so that just blew me out of the water. I was expecting to go in there and see my baby's heartbeat. So, my doc talked of a "blighted ovum" "missed miscarriage" all that, but said she wanted me to come back in a week to do another u/s, but she said it didn't look good. I went back the next week, and same thing, empty sac, no changes. I was totally devastated!! I had no signs anything was wrong, no spotting, nothing, body still thinks it's pregnant. My doctor told me that waiting to miscarry natrually could take weeks, or even months. I just didn't want to go through all of that, still feeling pregnant when really I wasn't anymore. Well, technically I was, but not with a baby...So, I opted for the D&C. It was not painful. It was very easy. I went in, they put me under, I was out quickly and back home that afternoon. I had some mild cramps that day and the next, I bled somewhat like a period for a few days, then spotted for a week. I had my first AF back 5 weeks later. I have actually heard that a natural miscarriage is much more painful. But it is a very personal decision that only you can make. I needed closure, and I wanted to try again ASAP. That's where we are now. It's been 2 months since my surgery, and we are trying again.
Although my cycles are now very messed up. My last one was only 22 days. People keep telling me that you are somewhat messed up for a while after a miscarriage. I'm just hoping that we can conceive again quickly.
Definitely don't make any decisions until you are thoroughly convinced that there is no baby. Are you sure of your dates? Cause sometimes that can make a difference. And it's good that your doc drew blood for tests. Mine didn't do that, and if I knew then what I have sinced learned, I would've demanded it. If your levels aren't doing quite what they should be doing, then it's a definite sign that things aren't right.

Let me know if you need to talk. I never knew anything like this could happen. But after it happened to me, I discovered that it is actually really common. I know that doesn't help...but just know that you are not alone.