HELP WITH A PREGNANCY TEST!! (picture in post)

Audrey

I took 2 digital tests. I hear that they are not super sensitive when it come to picking up HGC...so I took the apart becasue they both said "not pregnant" the top one was from yesterday morning and the bottom one was from this morning. I know that digital tests have 2 lines already. but why did the faint line get darker?!?