How long before you get BFP?

Sim

As of now, my period is 12 days late but no sign of AF. No spotting too. Only symptom I have is nauseousness. Tested this morning and it’s BFN.

I’m always regular as clockwork and with my first 2 kids, I always got my BFN even before AF is due! So I’m wondering....

How late have you ladies ever gotten your BFP before?