Confusion

So I had a scan done at what I thought was at 6 weeks 4 day but we only saw the sack and York sack and it was Measuring at 6 weeks 1 day but no baby they said to come back when I’m 8 weeks but I don’t know when they would be! What do I go by geststation sack or by the embryo size of 4 week and 3 days. I’m so confused on how far long I am! I’m going to the doctors but not for a week or so! And also did anyone else not see baby and it all to be okay at the next scan?