Am I pregnant?

I’m late on my period by 8 days. My period is usually very very light, but there was never any blood, only some brown stuff on my toilet paper close to when I was supposed to start but it wasn’t much at all. I take birth control regularly and have for years, and never had any problems. I took 2 pregnancy tests, one last night and one this morning. After a few hours last night a very faint line had came up on the test. The one I took this morning shows no line. It says don’t trust the results after 10 minutes, but I cant help being paranoid and this faint line on the one I took last night has me paranoid. Anyone know anything about this kind of situation? The faint line was just a bit darker this morning than it was last night, but the one I took this morning is clear.