Am I pregnant or not???

Hi all, 

I recently posted a few days ago asking if the faint line on my pregnancy test was a positive or a negative but after reading a few reviews it says that it normally shows up two lines on a digital test and needs to be a third which I’m very confused about as I’ve never heard there being 3 lines for it to be a positive only knew there had to be two lines? I’ve taken a digital test that you connect your cartridge to a holder and It showed up “Not pregnant” but when disconnecting the cartridge it had two faint lines on each one

These are Tesco digital pregnancy tests.. has anyone else had the same results and turned out pregnant with similar results?