Trying to stay positive.

Laur
Yesterday we had our first dr's appt. I was supposed to be 7weeks 3 days according to my calculations. They said I was supposed to be 8 weeks 3 days. 
The baby, unfortunately, is measuring 5 weeks 6 days. No heartbeat detected. 
Due to the fact that I ha a miscarriage in June, I am heartbroken that we could be going through this again.  The dr encouraged us not give up yet. I'm still waiting on bloodwork to come back with my hormone levels. 
Anybody have a similar situation? Any positive stories of babies measuring behind and growing full term?