Mixed feelings on test

Kristen • 24,married and trying for my first,after a chemical pregnancy July 2015.
So I took a pregnancy test and I got a faint faint line and then it got darker few after that,it was right at 10 minutes. I'm keep being told its positive,but I've heard evap can look the same,so I'm worried,anyone had the same result on it be positive? I was only 3 days late,I'm 4 days late today plan to retest Sunday morning.