Doppler readings accurate?

Chelsea
I have the sonoline b Doppler I use on occasion and it almost seems as if it picks up my heart rate and combines it with the baby's. It's very hard for me to get a heart rate of 140+ which is what the baby's always is. It'll be smack on hers, but read as 97 and I know damn well that heart rate isn't 97 lol anyone else have this issue?