8+ weeks, no heartbeat.

Cassie
Went to my first US today And they weren't able to detect a heart beat. She didn't mention measurements, didn't show me the monitor (didn't ask). I'm supposed to be around 8 weeks (likely 6w earliest).
She said I still might be earlier than I thought. I just got a phone call from them about coming in for an appt on Thursday to go over it. 
Not sure what that means but I'm terrified. I've already had one miscarrIge at 12 weeks and I was really looking forward to having this baby.