There is a fic floating around the internez, by way of the Way Back Machine, that has Buffy hearing baby Connor crying and spontaneously lactating, thereby "proving" that she is his real mother.

Sorry Darla.

It's a very vague recollection I have but in it, or possibly another fic - there were, heh, several - the Powers took the fertilized egg from Buffy after IWRY and kept it safe or something until they could 'put it in' Darla.

Yeah, nope. Not creepy at all.