Can I walk on my sprained ankle?

I just sprained my ankle this morning. It started to swell up right away and felt really tight. There isn't a lot of pain (but that may be because I took some ib profin) and I have kept it elevated and iced, but I really need to be at school in an hour and I don't own crutches. Would it be fine to walk on it if I'm careful? I've never sprained or broken anything before so I'm not sure what to do in this situation.