Doppler and heartbeat?

I am 9w4d. I went to my initial appointment today. My Dr. tried to find a heartbeat with a Doppler, but didn't have any luck today.  She did say it was still a little early and there was only a 15% chance we would have heard it today.
I will go back next Friday to check again and if we don't hear it again I will go back again the following week before our 12 week Down's syndrome testing and ultrasound appointment.
Any encouraging words?