Sometimes all it takes is to ask. Be persistent, too. Often a guy feels weird coming straight out and talking about his feelings. (Feelings aren't manly!) However, if you push hard enough, he'll tell you. Pay attention to his tone of voice. That could be the only sign he's not hurt. Just make him feel comfortable, and you should have no problem. Best of luck!
if you ask too much though, he might think he's supposed to have hurt feelings, or he might get upset that you didn't believe him the first time he told you he was okay. so there are some problems that might arise with being persistent. you should know your guy, so just do what feels/seems good.
Get a clue, if you have to ask this question, you know the answer. He's hurt. And he is probably not talking to you or talking very much.