misdiagnosed miscarriage??

Anne
So, we are supposed to be 9w4d today. We went in for our first appt and they did a transvaginal ultra sound. There was no heartbeat. 
My question is, could this be a misdiagnosis? 
Should we get a second opinion?
I'm devastated. We lost our baby boy last year at 13 weeks. I am having a hard time believing this. 
The doctor told us to come back in two days for another ultrasound. So, this is where my doubt comes in. 
Please help me!