I bought an AngelSounds fetal doppler. I've attached a picture of it so you'll know which one I got. I'm 12 weeks pregnant and have no problems finding my baby's heartbeat. The problem I have is getting the machine to register the heart rate. If you have used this machine before could you give me some advice on how to do that? I've held it there as long as I could with the little digital heart showing, but it never gives me a number. I'd appreciate any advice! Thanks!