It is tough enough for the beat cops to keep up with their own state's registration laws, let alone the other 49. The officer probably won't have any idea what the requirements for KY are. I used to keep a sheet in my clipboard that ran down what each state's registration requirements were, but I ran into that issue so seldom that I eventually discarded it during one of my periodic re-organizations. Heck, in my state you get a 6 day grace period, anyway, and your honset explanation at the roadside would probably get you out of a citation from me, at least (though I never have been big on writing tickets; "voluntary compliance" are my buzzwords).
You might get a ticket, but I'd say the odds are low. Just make sure that you register it as soon as you have finished your move.