sprained ankle

I was goofing off with my kids and sprained my ankle on Sat. :rant3:Pretty sure it's not broken as I can move it and bear some weight on it. Problem is that I still am trying to finish training for the Big Shoulders Swim in a couple of weeks. I was in the pool today, and while I could only swim freestyle (other strokes hurt too much on the kick) with less of a kick and funky one-legged turns, the ankle actually felt better when I got out than it had since the injury. Has anyone else had any experience with training on a sprained ankle? Any idea how long this is going to hurt?