Maths A/S Level early?

I'm in middle set and I so far got all A*. I have complete module 1 and module 2 (edexcel) and have only module 3 to complete

my friend is in top set and he has already done all three modules long time ago and he said he is doing a/s maths!? is this true? is this the real a/s maths that i am going to do next year in year 12? and he said he is going to do a test will that be an a level completed and what if i does a/s level maths in year 12 is it the same thing?

im confused.