Boyfriend is weird after sex?

Is this normal? I really love him. And before we have sex he is usually really sweet. All his attention is on me. He wants to hold me and tell me how he feels. But then after sex he is really aloof. Like he will cuddle with me but i think thats only because he feels that he has too. And he always wants to go do something else like ten minutes after cuddling. He will usually just go to sleep. Or get up and go eat. And it just seems like hes not as nice as he is before we do it. And its not even like its an obvious change its just the little things. And i don't think he is doing it on purpose. Could it be that he doesn't love me?