Quick home test question?

When I looked at the control zone of my first test there is a straight dark defined line surrounded by a thick bar. When I looked at the test zone of my first test there is no defined line just a faint bar. On my second test (5 days later) there is a darker bar and just the very start of an actual line starting on the sides. Just a little wee bit on each side. The instructions show that a fail has nothing in the test zone at all, no line or bar. so now I am confused. Does the bar mean anything or does it always appear.? Does anyone even know what I am talking about when I say a bar surrounding the defined line?

I'm not sure which kind of test kit you're using. On the ones I get, it has a control line and test line. The control line is to make sure the strip is viable the other is for thc. If there is a faint line on thc it means you're clean.