Given a chance to change my career, i wouldnt because i like what i am doing right now. I am a network engineer and really happy with my choices. when i was young i too was confused and whated to be a civil engineer. You are at a stage where you can change your career so that you grow in a field that you are passionate about.
you can always take up BIO as additional subject and later in college choose biomedical engineering as your major.
Again if you are not sure at that point, in college as well you will have options to choose minor subjects so that you can have different options to decide your career path. Always be open to new opportunities and try out different options to be sure if you have any doubts in mind :)