Heartbeat?

Looking for positive stories while I wait a week for my next appointment 
Went in today for my 6 1/2 appt and they saw a gest.sac and yolk sac but no heartbeat ,sono tech took several measurements and some show me at 6 weeks and some only at 5 weeks 3-4 days ,I go back in a week ,dr didn't seem too concerned ,who else had to wait to see a heartbeat?