A clever portmanteau of "pregnant" and "paranoid"; generally used by females to describe the unsettling feeling following an unsafe (hetero)sexual act.
A socially acceptable/reasonably polite acronym a guy or girl can either text, message, or say to a person that persistently hits on them without a clue as to how disinterested they are.
Nah, girl. I told him to BFO, so I'm done with that shit.