What would cause this change?

I took the above test at 9:30 🕤

Someone suggested I take another one in two hrs. I waited until noontime so 2.5hr later to take it. I didn’t have any water during the 2.5 hrs

One looks so close it could almost be positive and the other is clearly negative.

Did I miss my surge?

Should I count the purple test as positive?

I’m confused 🤷‍♀️