Yeah worst case scenario for me is to retake a unit. And wow an A in unit 1, well done! As long as you have perfect answers and you manage your time wisely, I am sure you will be fine.
My other exams were a bit of a bundle of feelings! I was pretty stressed considering I do 5 subjects and my exams lasted a month and a bit, and one of those weeks I had 5 exams. Some were decent and some were just torture.
Are you thinking of going to University?