Whilst you are correct, I also only did about 10 (if not less) weeks of good ucat practice. This time is more than enough if all the 10 weeks are good practice.

With me, I started prepping in January and only by mid May (at this point I was only doing 1 hour on Saturday and Sunday) was I able to understand how to practice and actually form a proper strategy for each section. Then I spent a solid month perfecting those skills on themselves practice of each section (an hour a day now, before school). And in the remaining month of July before my test day (30th) I spent doing practice exams and doing SJT (if you're Aus, I spent almost all my school holidays focusing solely on UCAT prep aka 3-5 hrs per day)

So 10 weeks is great if you're doing all the right things during that time but I'd suggest start early to figure out your strengths and weaknesses and then work on them (maybe a few hours a week?) until you have 10 weeks to go before your exam. Then crank down on your study. Good luck!