Bad girlfriend?

Destiny
Ok so the guy I'm having a baby with ( my boyfriend??) is mad at me and I feel like it's ridiculous. My ex husband just sprung on me that after all this time of only seeing his son every other weekend he is going to keep him for an entire week. He has never been away from home or me for that long. So I wanted to take today as just a mommy and son day or as my son called it a batman and robin day. I told  my boyfriend that since I had spent Friday night and all day Saturday with him that I was going to spend today just me and my son before he leaves for a week. HE IS PISSED. Am I in the wrong here? I think it's ridiculous.. Be honest with me. If I am in the wrong tell me.