Thanks for all the feedback guys, sorry for not replying for a while. I didn't know about the access course and I think it's a great idea for people who may have changed their minds during a level. Taking chemistry outside of school would just be too much work, especially as my other subjects are all quite heavy, and also it would be too expensive seeing as I'm already paying to go to sixth form. I think I'll continue with my original options and then if medicine does become something I decide to pursue I'll just go for the access course. Thanks for all the info though guys, much appreciated!