Please help! I don't get it.

Allie • Happily married 12.27.16 Mother of three wonderful boys 💚Dean,Erik and Finnegan ❤

I don't get it. did I miss it? Please excuse my ignorance, as this is the first time I've used opks. but have I missed my window?

the top one is at 1:33 pm bottom at 7:43 pm. if anyone can help me out, I'd greatly appreciate it.