I don't want my mom in the delivery room

I'm 21 and as of right now, the father of my baby doesn't want to be involved. So chances are he won't be in the room. My mom keeps talking about being in the room during delivery but I just don't know if I feel comfortable with that. I would honestly rather have my dad be there because he's my best friend and he always calms me down. I told her and she was extremely offended. The reason I'm not comfortable with it is because we are complete opposites and she argues about everything with everyone in the family. She makes me extremely tense when she's around and I don't want to feel that way while giving birth. She also lately has been pushing baptism and religion on my child saying "I would hope you get her baptized otherwise that's pathetic. You're child needs to know god. You need to start going to church". Then she guilt trips me saying "oh I thought you believed in god I guess not wow". Just because I don't want to baptize my baby doesn't mean I don't believe there's a god. She will not leave me alone on it and gets angry when I tell her to let me decide what I do with my own child. I just don't know how to get her to realize she is making me not want her in the room even more. It's seriously a daily thing for her to argue with at least one person in my immediate family because she always has to be right. It bothers me that it hurts her because I obviously do love her but I just can't have her in there. It would be a nightmare and I don't know how to keep her out without hurting her feelings