Went to Dr today to listen to heartbeat on doppler. Took nurse a while to find, she finally said she found it and we listened, too excited to really pay attention. She said it was reading 166 bpm. Im 10.5 weeks so that's a good rate she said. But when I got home I started listening to it and it sounded really slow compared to others I've heard so I counted and it came out to 90/100. Could this be my heartbeat sound but still accurate reading on doppler and nurse was just too impatient to find the babies? I'm just confused