I'm thinking about sitting as a private candidate for Computer Science, and possibly maths and physics. I believe I am able to self-teach these topics to myself, and may even get through CS in a year and sit the exam early. I would like some advice on how to do this, I'm trying to get UCAS points for things like University, and would these qualifications still be of any value if I do not go to university immediately? Or can I (at 17) go to uni with them? Advice please.