crying after feeds and teething!?! help!

So my baby boy just turned 3months old and for the last month he's been crying after almost every feed. He drinks 5oz with rice cereal(as of 2weeks ago to help with reflux) and when he's finished he just starts crying hysterics and screaming. Then putting his hand back in his mouth and bitting. Could this be just because teething? Or could he still be hungry? Mind you I've tried giving him a little more milk and he still cries.