I have a question about taking pregnancy test?

Courtney
Ok so the top one is from this morning and the bottom is from last night. I went to bed thinking it was negative but when I got up this morning I found two lines so I wanted to retest. But I think that the one I retested with is from a new box. Which isn't doing anything! I think it's a dud! Has anyone ever come across that? Oh and I'm four days late for my AF