I had a missed miscarriage in sort of similar circumstance, 4 days after my original ultrasound I had a second which showed the sac was not complete and therefore "unviable", I think this allowed my body to miscarry. 

The upside is that I fell pregnant immediately afterwards, and haven't had a problem a second time. 

I hope it all works out either way.  Best wishes.

Jodi

Hi

I have had blood tests for HCG levels but for different reasons, I had two miscarriages and an ectopic. What the hormone level will tell them is if the pregnancy is progressing as it should, it should double every two days. I know it is hard, but all you can do at the moment is wait it out until you get the blood test results. I hope everything is okay for you and baby.

Lorna x