Best friends wedding advice!!

My best friend of over 15 years is so excited that I'm having a baby! She loves kids and doesn't have any of her own yet. She's getting married about a week and a half after my due date. I'm aware baby can be early or late but I keep telling her I need to see how everything goes before I can give her an answer about being there. I would love to atleast be there for the ceremony regardless of how crappy I'd be feeling, but can't see myself taking a baby that young around so many people. I also plan on breastfeeding so I don't know how plausible it would be for me to go without my baby even if I pump. Does anyone have any advice or think that it would be possible for me to still go? Or even how to tell her that baby is definitely not going but I may? She has made quite a few comments about the baby being there and after the first time of saying "It wasn't happening" nicely, I just keep avoiding the topic or saying "we'll see". The ceremony is about an hour from my house. I believe she would understand eventually, but she has no young kids in her family or know anything so she doesn't really understand I might not feel up for it mentally/physically and that baby will be too young.