Just don't get locked out of your room like I did when I was about 4.5 mos pregnant! We put our room key too close to our credit cards or something because after going to the nearby pool, we went back to our room, dripping wet (and of course having to go #1, being pregnant), and voila! No access to our room! It took a long time to get somebody to come our and let us in!
Well, now I look back and I can laugh and I do think fondly of those memories!
At any rate, enjoy yourself, take a dip in the pool (don't get locked out), go for walks, sit on your balcony - the balconies are HUMUNGOUS! You may be able to watch golfers or have a nice water view. I would bring a few good books and really relax (if that's at all possible with your other DC in tow)! The main check-in area is a place to visit if you want to get out. There is a small shop and you can dine at Olivia's. We did this one evening, then took the boat over to DTD. It was very nice and relaxing. I enjoyed the boat ride.
Good luck and congratulations!