Always go for it. You might get rejected, but you'll always wonder if you don't even apply. Also, if you did it in two weeks, tell them that! If you've got the quick thinking personality that can back up your claim in the interview, you'd be surprised how much that impresses them. I barely scraped the entrance requirements, but still got into St. A's, Durham, Bryn Mawr and UPenn--because scraped I might have, but all my A-Levels were self-taught.