Please take a look at my test

Kayleigh • I'm Kayleigh. Got a beautiful daughter called Lyla who was born on 22/02/2015
I took this about an hour ago. 
I done 2 tests last Wednesday 2 days before AF was due.. I done a clearblue Thursday afternoon which said pregnant 1-2. 
I've continued taking tests but there still really faint. 
According to this app I'm 4weeks 4days.
Ain't the lines supposed to get darker? 
I know I either conceived on the 9th or 12th of July my AF is 5 days late now.