Am I wrong?

My boyfriend went to go to a snowmobiling race. I live with him and his family but he never told me about this race. Obviously I knew it was gonna happen because his dad was talking about it. They own a snowmobiling store so it's important that there there. His friends came over to the house this morning, wake him up and left.

Now here's the thing. I'll be 39 weeks on Monday, I could go into labor at anytime. And he just leaves? Didn't even really tell me about it, but I knew because I heard conversations.

Should I be mad because he left with me being super pregnant or

Should I just be okay because all his family is expected to be there?

Also, he didn't invite me to go. For that matter none of his family invited me, but I didn't want to go anyway because I don't want to be standing in the cold watching races so it's not like I was gonna go anyway.

Am I overreacting :/