Webi've passed dozens of tests as a regular user, and so long as i get a faint line, it's off to the lab! Home tests are a must though, and for that reason. If you pass a home test, you. Webmost people do know a line is a line and is why the test show a faint line as negative its literally on the test. Hi u/imaginary_bother_200 , lines can stay in your urine anytime.