Help!

So I went to dr on the 19th they said I was 5 weeks 6 days based on us measures.... But this was a VERY zoomed in us . So I went back today thinking i would be a little over 7 weeks. And the baby is only measuring 6 weeks 1 day! The dr at first was concerned. But when he looked back at my previous us he said that it was very zoomed in and he didn't have to zoom at all today. And that could be what the problem is. Has anyone had this before! I'm so nervous and scared I will attach both pictures below. The top is from the 19 the bottom is today.