rahemanfiras

hi,
ive just started year 12 and am thinking of studying medcine in 2010 entry,
i just wanted to ask whether universities mind if you have a practice go at the UKCAT exam in the test centre in year 12 and then, do it once again in year 13 when im in my A2's,
im just confused on whether i should have a go at it this year and see how i do, and am worried that med school's might think that its a bad idea.
Please advise

thanks
FR