You'll be taking 2 x maths, 1 x physics, 1 x chemistry, 1 x biol /mblg each semester.
So the credit points would be (2x3) + 6 + 6 + 6 = 24 each sem.
I think you can overload (not too sure), but it'll probably jeopardize your results for the rest of the subjects.
I guess we can do it in year 3.
hope that helps.