I'm not sure if this message will be a hugely comforting read but I hope it is!
With my beautiful, happy bouncing IVF girl, I never got 3+ weeks (despite my blood HCG being really high as she started as part of twins!)
With my very sad IVF loss I got 3+ fairly early on.
I was very much like you with the testing, and spent weeks agonising over lines. In the end it made little difference to the actual outcome.
I remember my first test at 4DP5DT in the evening, getting my first positive with my daughter. I was obviously elated.
Expected it to be darker the next morning so did one again.
Negative.
I don't need to explain how I felt that entire day. The evenings test? A darker positive.. turns out I'm just crappy at hydrating in the day, but drink tons overnight. So my positives were evening based.
All this is to say that whatever that test says, whatever the symptoms are... nothing can really indicate what's going on in there.
They say the wait to hear how your embryos are is hard, but the TWW is harder. Then the wait until first scan harder still and the wait until the 12 week one is damn near impossible.
It's so hard and it's such a whirlwind but all I can say is that for now you've got a cracking positive test there and you're pregnant. Beyond that fact, they really do tell you nothing!
Wishing you all the very best after such a tough journey. X