I had mine at 32 weeks, to the day It was fantastic, it was at my place but friends organised the entire thing, I didn't have to lift a finger! The belly was big enough for everyone to have fun with it (lol there were loads of pics taken) but not so big that I was uncomfortable.

Even so, the day still exhausted me. I reckon any later, or if I did it all myself, I would've been passed out half way through lol