The college im going to is only allowing me to do 3 A-Levels (History, English Lang and Politics) would having an extra AS level in Law give me and advantage or am i better off just focusing on the three?
If you can cope with the additional work then I think you should do 4 AS levels otherwise you'll be at a disadvantage over the students who have done 4 AS levels when applying to university. When I called a university to apply on results day they asked me which AS level I had dropped and the grade I got. For some uni's you can get points from the AS you dropped which would help if you didn't do as well in your other 3 subjects.
If you can cope with the additional work then I think you should do 4 AS levels otherwise you'll be at a disadvantage over the students who have done 4 AS levels when applying to university. When I called a university to apply on results day they asked me which AS level I had dropped and the grade I got. For some uni's you can get points from the AS you dropped which would help if you didn't do as well in your other 3 subjects.