Girls, could you please help? My baby will be 3 months old in a week. For about a week now, he's been quite restless, constantly putting his fist in his mouth and biting his gums while getting upset. He even took my finger and started biting it as if he were chewing. Previously, he could suck on his fist, but now he's acting very irritable. Could this be a sign that his teeth are about to come in?