HELP?! late period!

Amber
Ok, I have been using this app since August and my period has always been spot on! I either start the day that it tells me or he day before. WELL, I was suppose to start Friday but it's now Sunday and there is no signs of AF! I took a pregnancy test and it was negative😩 
P.s.~ this month I felt like it could possibly be my month because I had a lot of cramps and my sense of smell has been insanely good! I could smell my kitchen trash all the way in the living room and my husband thought I was crazy!  
Could I still be pregnant even though I'm not getting a positive on a test yet?