Doppler

Natasha
Hey everyone! 
So I am 10 weeks and 3 days along and I got my Doppler in the mail today! I tried it twice and I still haven't heard anything, I'm 90% positive I heard the placenta but I just can't seem to find the heartbeat. I have a tilted uterus so I don't know if that has anything to do with it but is it normal to have difficulties finding the heartbeat at 10 weeks?? Any and all advice is greatly appreciated!