This might be a silly question.

Meg • 👨‍👩‍👧‍👧. Mom to👧. 👼. 🌈👧🤰

So this morning I took an opk before work it is pictured the top one in my photo. I took one tn when I got home from work and it looks positve. My one this morning was not positive. Is it possible to get a positive at the end of the day like this when it wasn't this morning?? Sorry if this is silly. I just dont know how it could jump during the day.