App for HB

Ronna • SAHM to my amazing 3 year old Princess. Baby Borja #2 on the way. Due 12-31-17
I just downloaded Baby Beat... got a HB of 139 it was pretty cool, that was the highest it defiantly jumps around. I heard mine too which was 72 so it has to be somewhat accurate but it's not like the doctors. 
At least I saved and heard one LOL
Do you think the numbers are off... I do...
 Any experience???