Lines not darkening

Ashlee • 20 years young (: ttc rainbow baby. baby dust and sticky baby's to all!
I got my first faint line on 3/1 and I was only 9dpo. Af isn't supposed to be due until 3/6. My lines just aren't darkening. Is that normal since I got my first line so early or is something wrong? The lines are definitely still there, just light. For example top one was this morning, bottom was yesterday morning.