Have you been to open days? You still have time to visit universities and see what students think. These two degrees are very different from each other so you should think about the career you'd like to go into, and look at reviews from Which?University and UCAS, as well as look at previous threads already made on TSR that have a lot of replies to make an informed decision.
Personally, I'm not studying Law yet but I'm going into it having done work experience and enjoying the work I've done with law firms. It's a fantastic gateway degree to do a lot of careers, not only Law so that in itself is a huge bonus but if you are looking towards the science route Law will be no use.