@really123 - @collegemom3717 knows more about this than I do, but I believe that Oxford takes some ridiculously small number of international students (like six) into their medicine program each year. I would view the SAT/ACT as a hurdle rather than a key determinate of your success. Your admissions test and interview performance will have significantly more impact on receiving an offer than an extra 50 points on the SAT. There were students who absolutely crushed the MAT last year who did not receive offers, most likely due to poor interview performance. For a US math applicant, the MAT performance has much more meaning than your SAT/AP scores.
My son had English Comp, English Lit, US History, Comp Sci A, Calc BC and Physics C (both) done by the time he applied. He did micro/macro senior year but they never asked to see scores for those.