Definately watch what you eat/drink! Also, I bought a cute "tankini" type suit from Lands End...it has a skirt(with bathing bottoms attached) and a matching spaghetti strap top. The top and bottoms meet in the middle so nothing shows and the BONUS is that the skirt bottom conceals the pouch when it fills. Since the first suit, I've purchased other tops (most department stores have mix/match suits now) that match the bottoms so I don't feel like I am always wearing the same suit.
Don't stress over it...Have A Great Time! I'll be there in two weeks and looking forward to it, too!