Before anyone starts, I know that as soon as you open a test it becomes invalid. If that is response please move on.

Question, because I like a huge group open my tests mainly because I save them for my fertility journey. Do all digital test always have 2 lines? I've been seeing different articles online and some are saying that they do not always have 2 lines. That the ones that would have 3 lines for positive are the ones that could tell you how far along you are.