Should I retest....?

Sara

So, I took a test on the fourth, and I saw what I think is a positive line. Faint but positive. It showed 5 minutes in. (Both tests I took only say not to read the result after 10 minutes. Faint lines showed up on both tests 5 minutes in to be exact). Anyway, I sent both to a friend, and they said it's probably just an evap line. I'm at a loss. Should I retest, or am I actually pregnant? My period isn't supposed to start for at least another week. The blue test is from the 4th, and the purple is from yesterday, the seventh.