Mommy, how does the baby behave with teething? We're still early, but …

Mommy, how does the baby behave with teething? We're still early, but such a thought crept into our heads. He doesn't pull out the fists from his mouth, he chews so much that it makes a noise. He's been capricious all day, sometimes he doesn't take the breast right away, through a tantrum. For the first time, he's been crying all day. I don't understand what's bothering him ?