where did you find baby's heartbeat? with Doppler.

I'm 11 weeks pregnant and I haven't find the baby's heartbeat at all with the fetal doppler. Anyone know what areas to really look? I thought baby would be next to my belly button but I heard they're all the way in the pelvic bone area? But right in the middle or is it possible they're somewhere on the sides? 
I'm new to all this and I've been trying since I've been 10 weeks lol