3 weeks positive pregnancy test

Hello, went to the OB the other day and they dated me at 6w0d. (6w3d today) but I found out I was pregnant on the 2nd of July. That would have put me at 2weeks 6days for a positive pregnancy test. Is that normal? Or could I be further than I think?? According to my last missed period I should be 7w3d and blood work supported that idea. Not saying doctor was wrong, just wondering if it’s maybe too early to know for sure how far along I am seeing as the ultrasound was for confirmation and not a dating scan!

Pic of positive test I got on 7/2!