manukev, I'm a "born-again biker" after 20 years, and sat the theory test last year before getting the A provisional licence. (have a full car licence too). I know the number of questions have increased since late last year, but I didn't have any difficulty with the test - a week's study and practice will see you through with no problems!
If you're going ahead, I suggest you move quickly - there'll be a change in the law soon which will prevent you from getting a learner permit / bike licence until you've completed 16 hrs of compulsory training. (don't get me wrong, I think training is great).
Good luck and safe motorcycling!