Nervous...

Lauri
I'm a STM and am 7w3d. I had an ultrasound today and I'm measuring at 7w1d but still didn't hear the heartbeat. I saw it a couple brief times, but my dr said it's too early to catch it to hear it. Anyone else know if I should be worried or not!? I cannot remember when we heard the heartbeat for the first time with my daughter.