Momshie, faint lines can be tricky kasi sometimes it's the dye running or the test itself, pero if you're seeing something kahit super faint, there's a possibility! A few of us tried taking tests too early at nakita namin ang faint lines na nawala the next day, so timing talaga ang key, best to retest after a few days or a week to be sure. Since you guys use protection, the chances are lower pero hindi impossible, so if you're worried, get a blood test from your OB para sa definitive answer na mag-ease ng mind mo na talaga. Keep me posted, sis!