I have a doppler from home, and I can find the baby's H/B no problem, but it seems like it's fluctuating. My OB taught me to count how many beats are in 6 seconds, then multiply it by 10, and that will give you an estimate heart rate. The first 5-6 times I listened it was always 160's, the past few times it's been slower, like 130's, 140's, then when I find it, it seems to speed up to 150's-160's again, is that normal? Maybe the baby sleeping then becoming active?