do you have another one to do tomorrow?
I haven't used that brand, but I can say that mine have reliably kept the same darkness from 5 mins to 3 years!
So I think your photo is valid. but you're right, its hard to tell. I say todays looks darkest... not sure if its dark enough to be positive yet.
you can pull them apart to just look at the strips inside, sometimes easier without the reflective plastic.

fertility friend has opk galleries, but they don't seem to have forelife.