As long as you do Maths and preferably as much Further Maths (at least AS but A2 is better), you should be fine. Physics is also a bonus because it's fairly mathematical and gives you grounding in a lot of Mechanics-type stuff that comes up in uni Maths (and A-level Maths for that matter).
FWIW, I did Maths, Further Maths, Psychology and French to A2 and Music Tech AS.
[EDIT:]
zdo0o
someone on this forum (can't remember their name) is currently at cambridge doing maths, having done maths, further maths, french and psychology at a level.
i did maths, further maths, french and physics to A2 and AS chemistry.
i got offers from (all with AA in maths and f maths): Oxford: AAA Warwick: AAB +1 in STEP/ Merit in AEA Durham/Bath/Bristol - i think these were all AAB
Cambridge: AAB+1,1 (you won't get this any more, i think the standard offer has increased to A*AA+1,1) Warwick: AABb+2 Imperial: AAA (12 a modules in maths+fm) UCL: AAA (including A in maths and fm) Bath: AAB/AAC+2