Late period

Okay so a while ago my period seemed to be sometimes irregular starting a day late and such but for the past few months ive been using glow and another app as well and every day it said i was to start it happened im ttc for my second and well i was supposed to see af on the 11 and i still havent ... I guess im just really hoping this could be it but i tested on the 11 and it was negative could i possibly be pregnant or is it normal to be two to three days late? Ive always only been one...:(