I'd go (or at least plan on going because you never know whats going to happen). I was going out doing stuff right up until the day before I gave birth and went on a big shopping expedition the day before I went inot labour. I was planning on going to a friends wedding a week or so before Claires due date, but I didnt go as I was in labour and giving birth that day. Just leave a bag in the car if you are worried, just in case! I'm sure they'll understand if you need to leave early or decide on the day you dont feel up to it.