I had my GP try at 9 weeks with DD2 and we did hear it, but she was very surprised to hear anything (DH can usually hear my babies' heartbeats by putting his ear to my tummy by this stage too). I had a Ob appointment at 14 weeks with this baby and they wouldn't even try to listen. I think it might just be a bit too early for you to hear anything - it must also have something to do with where the baby is sitting and the position of the placenta so early on as well. I reckon if you can hear it early, everything must just be in a really good position for listening.

Sending lots of sticky vibes your way. Try not to worry