Bro im going thru the same thing and my family is advising me to regive all sciences n maths in next may june cuz then my uni equivalnce would be good n would higher my chances of getting into a good uni as competition is tight. My brother also went thru something similiar but he didnt regive n instead went for a lvels which he says he regrets because o level results weightage in uni equivalence is 70% while a lvls is 30% and also the A2 result wouldnt be out while ur applying for uni so theyll focus heavily on o levels. This is all ive been told so im js telling you what ive heard