AJ McCarron finally got some action this season -- well, enough to impregnate his wife at least ... 'cause Katherine Webb is pregnant!!
The model and the Cincinnati Bengals backup QB just announced they're expecting -- and she's 4 months along the way.
"AJ and I feel beyond blessed and grateful to FINALLY announce after 4 months we have been keeping a secret! We are having a BOY!"
"Thank you all so much for your prayers for us as it hasn't been an easy journey. We thank God everyday for this wonderful blessing and can't wait to share this journey with all of you!!"