Not good news

Anna
First ultrasound to date, no heart beat.
​Fetal pole is measuring 1.2cm and they said anything over 7mm should have a heart beat and I'm only measuring 7 weeks.
​I'm not sure what to do. My drs office doesn't open till Monday 9am, I want to think it's a mistake. I had my period April 29th, didn't ovulate till may 23rd, could they be wrong?