Having been a Maths/Further Maths/Physics/Chemistry (and electronic engineer..) geek I would say the following.....
Physics is probably the most relevant if you want to fly, to gain an initial understanding about all those things you will lean about in the tech's for the ATPL. Trust me, most of it is there! Maths, yup useful. But the other 2 - I like people in the cockpit who can offer different things, that probably means do what you like doing provided that you ain't going to mess up, and also make sure it will not hinder you on your chosen path.
CCCC.....ough