Going to be a long two weeks

Nicole
I went in yesterday for an ultrasound guessing I was 7 weeks 3 days. I don't know remember what day my LMP was in February. I am guessing mid February. I do know the day we had sex but my sure when I ovulated. 
All they saw was an empty gestational sac - not even a yolk sac. That doesn't sound promising to me. The sac measured at 6 weeks but I would think you would at least see a yolk sac by now. 
I got my labs back and my hgc levels were at 74,552. I don't plan to go back and see if they are raising. My doctor said the labs looks good and we will just wait on the repeat ultrasound in two weeks. 
Anyone have a similar case where they didn't see anything (not even yolk sac) and then boom later they saw a baby and heard a heartbeat? Waiting game is hard.