Wait for your grades to come through. I would say if you get a C or above take it. A D or below... maybe not. I have applied for neuroscience (at Leicester) I imagine it does have odd bits of chemistry thrown in here and there. There is no escaping so how much do you dislike it/struggle with it because it will come back to haunt you in uni again and again. Which part of chem do you struggle with?
(Assuming you're with OCR) the maths/mols side OR the organic chemistry (i.e. chemical formulas, equations, mechanisms)
You have to be quite good at maths/mols side as with OCR sets an exam worth 50% of your A2 grade which is purely maths, mols, equilibrium which I despised.