I need some help

Please don’t be rude about this just help me understand. Yesterday morning I had a positive test but I wanted to double check so I took another one this morning and it’s negative. Last night I took one but I had just drank a bunch of water and pop so I kinda expected the one that I took last night to be negative but why is the one this morning negative?

Pictures

The first few with blue dye is from yesterday morning.

The second bunch is from last nights pink dye.

The third is from this morning with a clear blue test.