I remember my first test was super faint too, like I could barely see it and thought maybe my eyes were playing games 
Usually an evap line shows up after the test sits out for a while, but if you saw it within the time frame and it's pink/blue, it's prob a real positive. Early on the hormone levels are still low so the lines are lighter. I waited 2 days and tested again with morning pee and it came up darker. A couple of my girlfriends had the same and they went on to healthy pregnancies. If it's still faint or you want peace of mind, take another test in a few days and try not to stress too much. Wishing you luck!