Camping while pregnant?!

I know I may be a little crazy but I agreed to go camping with hubby and some friends over Fathers Day weekend. We'll be camping on a river so it shouldn't be too hot or anything but I'm worried I'm going to be SO BORED! As of now it looks like I'm the only girl going so I'm looking for some ideas of ways to entertain myself while the boys play. I'm sure they'll want to go hiking and things I won't really be able to do at that point. So...any ideas for me?