6 weeks pregnancy test

So I’m feeling paranoid I miscarried because my symptoms changed didn’t feel the same this past week although they felt strong today, but I got a pregnancy test to try to make myself feel better, When I took it the test line (first line) immediately got dark and the control line was lightish kinda dark. Apparently that’s a good sign meaning the hcg is so strong it took the color from the control line? Anyone else experience this or know anything about this? I’m hoping if my hcg was going down the first line would be lighter than the second one. I took a first response pregnancy test btw.