First time using OPKs..... Did I miss it?

Kayla
I am doing OPKs for the first time this month. My cycle is typically about 38+ days and I'm currently on CD 18. These are OPKs I have taken so far this cycle. The top is from Friday night, the middle is from Saturday night, and the bottom is from Sunday afternoon. The line seems to be getting lighter. Does this mean I missed it? Glow says my fertile week isn't until this coming week.