Testing after a positive and dr confirm...

Is it me or has anyone else not touched another hpt since their initial test? I took a test I July 9 and I was confirmed with the dr on July 13. I have not taken a pregnancy test again. My first ultrasound is August 6. I feel 100% pregnant so maybe that's why I haven't tested again, but I see so many ladies testing and wanted to know if I was missing something. Ladies who do test after being confirmed, what is your reasoning. I'm just genuinely curious!