Heartbeat @ 6 weeks 3 days??

Latasha • Had ectopic pregnancy of march 2010, had 3 miscarriages December 2012-march 2013 with drs help. Now pg w/rainbow baby!
So I have an ultrasound for January 9th & I will be 6 weeks & 3 days according to Drs calculations. I was wandering if anyone has heard the heartbeat then or was it later??