I though a fetal heartbeat is only detected from 7-8 weeks by a scan, i thinks its way to early to hear it with a doopler! When i MC in July the GP said its not worth using s doopler as nothing will be picked up apart from my HB.
Sorry to say but i agree with the others, its probably yours you can hear.
Sounds like your heartbeat! I agree with mosschops, these (heartbeat monitor things) really are being marketing by companies wanting to make money out of our anxiety - but should only be used by professionals. can understand if you've had mcs but don't these piece of equipment use some kind of sonic technology which must be disturbing for the poor baby!
I think people can find a doppler reassuring but with the caveat that you haven't been trained in using it and I'm sure a lot of people are listening to the sounds of their own body! Therefore if you have concerns about baby moving etc when you are nearer term whilst you might whip out your doppler you should also always be checked by a medical professional.