I did a first response test this morning it was a BFN so I threw in the garbage now I decided to take it out and open it up and when I take the strip and start looking at it in the back of the strip test I see a really really faint line that it's even hard to see my question is do they have the lines in the back always even if they are New and you have not done the test and they are just supposed to get color only if positive I'm so confused