So confused!!!

AF was suppose to show up on Monday the 25th it hasn't shown up yet. Today I had a little spotting but that is it. I took two test and one showed a very faint line and then took a digital one and it said not pregnant. I just don't know. In the past home pregnancy test don't work on me so I don't know why I keep spending the money. I guess keep faith and stay positive but so hard too. I mean my cycles are any where from 25 to 28 days and now 33 days,12 dpo. Ugh!!!!