Your GCSE are good, but not good enough for Medicine.. I agree with the other post, you really have to ace your a levels an BMAT/UCKAT, if you are very dedicated. Also, are you sure this would be right for you? Medicine is a very challenging degree to study for.
I was actually thinking of applying for medicine and my gcse's were 1A* 7A's and 3 B's, yet a levels were CCEU lol, even though I am passionate for medicine, I learned that science is really not for me. So I am now applying for Business instead with much better a level results!