Evaps

Do you get evaps on every test? I'm naughty and kept my last few tests. Every one of them has had a very faint line on them a couple seem to have popped up within the time some after but haven't changed at all. Digital said not pregnant and if I am I would be at least 6 weeks I would say? So am I right to assume these would be evaps if digital says no. I would usually have had had a pos by now with previous pregnancies. x