7 months pregnant, invited to Oktoberfest

My best friend’s husband is celebrating his 40th bday party this month and they are going to our local Oktoberfest. We are very close so it’s an important occasion but I am very preggo (will be 30 weeks), tired, and likely to be the only sober person for miles. I’m ok with that as I don’t drink much anyway, and I’m ok with others drinking but they tend to get really drunk and obnoxious and I don’t really feel like babysitting them right now. I want to suggest we meet up for a pre-party celebration dinner but I know friend will likely make it a big deal and be confused about why I don’t want to go (we already had this conversation last time they invited me to meet them at a brewery, it should be obvious imo). Am I wrong?