I’m going to take a slightly different tack from the other posters here. I agree with them, of course, that it’s too early to choose now. But what you can do now is maximize the range of choices you’ll have in the future. That means excelling as best you are able in all your subjects, including/especially the ones you may not like or don’t feel your greatest at. And for many students that means math. Being serviceable at math opens up many fields for your consideration, including many subspecialties of bio, which are getting increasingly quantitative these days.
So study hard, watch Khan Academy if it helps, and you’ll get to a place where you can make your best choice. Good luck.