Unusual....?

Ciddy
Ive been off pill & ttc for 4 months now. Since stopping pill my af has been pretty regular except last month I was 9 days late & no bfp! Af showed on 9th day. This month im now 12 days overdue, no bfp & no signs of af.... im unsure if I shud visit gp or wait a while longer....anything similar happen to anyone?