Can't find the heartbeat with my at home doppler

I am 11 weeks 3 days and I still can't find the heartbeat with my home doppler. ..I'm so nervous. ..I'm going Wednesday for my appt to hear the hearbeat and I'm so nervous being I can't find it myself...is this normal? ! I still feel pregnant, sore nipples, sleepy, nauseated and I didn't know if it was normal to still feel pregnant but not find an heartbeat...we have tried for 19m and I'm sp stressed when I go Wednesday they want find a heartbeat either :(