Weight loss and no heartbeat...

I am currently 10 weeks and at the beginning of my pregnancy I gained around 8 pounds but in the last couple weeks I've lost 6 of that and then this week I gained back 2. All in all I've only gained 4 pounds and to add more worry and stress to the mix, I can't find the babies heartbeat on my home Doppler. I think I can hear the swooshing noise of the placenta on the right side but as far as heartbeats go, the only one I can hear is my own. Ugh..... So frustrating.