Only yolk sac?

Kya

Is it normal for me to have gone in at 6 weeks 5 days (based on LMP) and for them to only see gestational sac and yolk sac but no baby? He said he might have seen a little flicker but wasn’t sure. He thinks i could be around 6 weeks instead and baby isn’t big enough yet. He also said don’t get excited. I’m supposed to go back soon waiting for call to reschedule U/S. I’m currently 7 weeks 2 days. Has this ever happened to you and everything was ok?