Am I in the wrong or is he?

Can you change your mind during sex? Me and my boyfriend were having sex I gave consent obviously. During it I just started getting uncomfortable and it started to hurt so I told him to stop and I didn’t want to do it anymore. He said “we already started we can’t stop” and he continued it got more painful so I started screaming at him to stop and then he said “you already told me yes I’m allowed to keep going”