You realise a C is the "average" grade, right? Therefore making you average for two and well above average for another two. Meaning overall, you have better than average grades. What subjects though may i ask? What course do you want to study? If you just want to get uni, you probably could get on on or two very mediocre courses with JUST those AS results already. Ideally, drop one of the C subjects, keep the other one and work hard at it. You could easily get AAA.