so confused about ovulation!

I'm so confused with all this ovulation testing. I have regular periods and been ttc for two months. Today is the fourth day of my fertile week according to glow and I've been testing for 8 days now with dollar tree tests and some first response tests and I can't even get a faint line! What's going on?! Is anyone else in the same boat and or have you gotten negative ovulation tests but still fell pregnant?