Why am I so upset?

My partner needs to go to the doctor today. We are already out so I thought I would come along. Since he always come with me to my doctor appointments. His mom called and asked if I was coming and he instantly said no and that he would drop me off. Like why can’t I come?

He invites himSelf to mine. I never really ask if he wants to come he just does. I guess we’re used to going to my appointments together. But he always like to do things on his own. I know when he doenst want me there. He could tell I was kind of like “why can’t I come” so he asked if I wanted to but I said no because I know when he doesn’t want me around. I just know. I know pretty well. So why should I?