Silly question for me, but when would I

Karolina • Still waiting for our baby.
This probably a silly question, but when would I be considered late? 
​I am on CD 27 and 13 DPO. AF due sometime between CD 24 and CD 27. I checked Glow and AF has not been past CD 27. 
​In the past AF would come between CD 24 & CD 28 and only twice came at CD 30. So I always tell myself if AF doen't come by CD 30 or CD 31 then I would consider myself late.  With all this info when would you consider me late?