I'm sure your friend won't mind if you decide not to go. You can never tell how you'll be feeling- I know that the last 4 weeks are the absolute WORST because all your body aches and pains come flowing right on in!

Look, if it was me, I'd probably tell your friend that you'd love to go but that you don't know how you'll be.

I think if you go somewhere that you're not sitting down for ages, it should be OK! I went to a charity concert and was in the seat for AGGGGES!! SO uncomfortable