Af 2 days and confusing pregnancy tests

Kayla • Wife & mama raising two babes with my angel baby Ada in heaven. ✨ 10/3/2020 Rest In Peace my beautiful baby girl. 💖

I posted this a couple of days ago but I need some more insight. I took this test a day before af was due and I can see a vvvfl line. I retested the next day with a pink dye and it was bfn. Should I wait a couple of days to retest or wait for af? I know blue dyes are notorious for false positives but I really feel like I see something. How am I testing bfn with frer but not with the other one?