I bought a fetal doppler online, the Sonoline B. I was warned its not easy to use before 12 weeks and sometimes overweight women  have issues with it. For the first few days, I couldn't get it to work, I was so frustrated! Then yesterday morning, I looked up some tips on YouTube and was able to find it within 5 minutes. Amazing! Someone described it as sounding like a dog panting and about 140-160 beats per minute. It definitely sounds like a dog panting! I was able to do it again and show Bill. Very cool to be able to use in between appointments!