i dunno.. how faint is it? post a pic! how long is your LP usually? are you "late" yet? it takes about 72 h for hcg to double, so you might not see things much darker for a few days. with DS i had a very faint line at dpo 13 and then still a very faint line around dpo 17, and then i forgot.. a few days after that too?? it made me so crazy, but not as crazy as he is making me right now right here next to me

but by faint i mean very light but no squinting necessary.
also do you have a chart online? maybe you o'd later than you think and you just got a very early positive! you can post a link and we'll check it out!!