2 year old kicks and screams every time he gets his diaper changed.. is this just a phase? he doesn't seem bothered any other time

Just being a 2 year : 2 year Olds have figured out they can sometimes get what they want through kicking and screaming, especially if they have wimpy parents. He is feeling you out right now to find out if you are wimpy. If he finds you are, then it will spread to other venues. So hold your ground here and show him who's boss. Be loving but firm, he's not going to get his way acting like that. Good luck!