Why are my lines all over the place?

[bassdesire]

Had light second line for a few days then very dark second line then took another opk and it was fairly faint second line. What the heck

I know how to use these darn things lol but why are my results all over the map?

 

[sprite30]

what brand are you using? are you testing at the same time everyday? once or twice a day?

 

[bassdesire]

Three times a day strips from amazon. Worked like a charm before so weird though!!