When did you first hear the heartbeat?

B.
When did you hear your baby's heartbeat with a doppler? I am 10 weeks exactly and my midwife couldn't hear a heartbeat today.
With my daughter I heard it with a doppler at 9 weeks so I am kinda stressing out... 
**Update** went for an ultrasound today and the tech said she did not see a 10 week old fetus..and asked me questions like "how do you know you're pregnant?" And "Are you SURE you haven't had a period since February??" Like I was lying or something. So now I guess I'm waiting for formal results from my midwife...