Lately I've been getting that echo on my doppler, where it sounds like you're hearing two heartbeats in different spots. It's weird cause if you shift the doppler wand around, you can hear the heartbeat in slightly different spots and it sounds a little different in each spot. And then sometimes I think I hear two heartbeats at once! I'm sure it's just an echo. At my 8 week ultrasound they only saw one baby. But sometimes I question the count my doppler gives me cause it flips around a lot, like from 130's up into 140's or 50's. That may just be the machine trying to keep up though lol.