Has this ever happened to anyone

So I took a clear blue test about 2 days ago now and then one like beyond that like 4 days ago and well I thought I saw a faint line on one of them but still thought it was negative so couple days after did another same thing. So left them well I have just come across them the one I took 4 days ago is the one out the too that's been left longest and there's no line no indent nothing but the one i took 2 days ago I mean it's a very visible line... like it's dark as hell in person is it an indent like of course it is right? As I've left it for days but is there a reason why this one has one and the other one doesn't... could I still be pregnant? I

As it ever happened to anyone else?its hard to see it clear but honestly it's soooo dark in person like what cruel person created these