I plan to take Biology, Chemistry, Maths and English Literature. I want to go into a career in medicine. People say that english literature doesn't go well with the others, but I enjoy revising it so am willing to put in the work.
Biology, Chemistry and Maths give you plenty of flexibility with a lot of university courses, so taking a fourth subject that isn't relevant could actually benefit you, your application will look much more interesting and, as long as you enjoy it, I would say it's a good idea.