Doppler?

Nicole • After having a miscarriage in February 2014, we just found out 7/9/15 I was expecting. We had our rainbow baby on March 20th, 2016! We are now going to start trying again to give our daughter a little brother or sister! ❤️
Being plus sized, what week were/are you able to hear your babies heart beat via Doppler? Thinking about getting one, but don't want to get it too early and be worried sick when I can't hear anything...