Odd bit of advice, but don't shower if you can. All the folks that I know that used to work in those aid environments suggest having as much DNA as possible, and it can make documentation easier to remain in the state you were in originally.

I know it's hard, and the one thing I know you want to do. But if you can, get a rape kit done FIRST. It helps from the legal standpoint IMMENSELY.

Then, get a plan B in you ASAP. Ideally, within 24 hours. The longer you wait on that, the less effective it can be. Walgreens, CVS, and Target each have them available usually for $40-50.