That's an excellent line! Especially in comparison to your earlier test.
My fmu is always best for me and I'm lucky to get even the faintest line with any other pee. But others get much clearer lines with pee other than fmu, it's so different for everyone. I wouldn't worry about when you first saw a line despite having had positives earlier on before because it varies a lot. Sometimes I have had lines as early as 7dpo, but I have also had lines later at 11/12dpo. I wasn't tracking my cycles with my children, only when af was due, so I was about 10dpo ish at a guess with my second and third but could be a few days out, when I saw my first positives.
I know it's always a worry early on, but keep testing and perhaps stick to using the time of day that you know gives you the best lines, this way you can keep track of progression more