Strong test lines, doctor confirmed...then faint line today?

I confirmed my pregnancy 2 weeks ago with the doctor. I was 5 weeks along, and I had 7 positive tests all different brands. I am 7 weeks today, and I’m such a nervous person I’ve been pregnancy testing myself every few days. I went pee today and forgot to pee in a cup to test so I managed to squeeze out a little more and test. The line was super faint. So now I’m nervous! I’ve had normal symptoms, occasional nausea, boobs hurt, cramping, no appetite, etc. Was it just because I used clear urine that wasn’t strong I got a faint positive instead of strong? I have an ultrasound tomorrow, I’m just so nervous!