I told my dr that I want to have an early ultrasound to see the heartbeat and she told me not to go in before 6w4d. If you don't see a heartbeat it might just be too early. I hope you do see it though. Good luck!
I think everyone and every baby is different. At 6w0d with my son we were able to hear his heartbeat, and it was 140bmp.
With this pregnancy, I went in this past Saturday for an u/s, the baby measured 6w3d, but we only saw a flicker on the screen. It was a little disappointing, but every baby is different.
Yes, but if you don't see the heartbeat, don't freak out!!! Even though your 6w 3d according to your last menstrual period, it's unlikely that your exactly that far along. You could be a little further along or a little earlier. When I went for my first ultrasound, I was measuring about 4 days behind. If that's the case for you, you might not hear or see the heartbeat yet.
Re: U/S at 6w 3d
Hope it goes well!
Good luck!