“I am 60% sure that I want to be a doctor”
Are you aware that it is EXCEPTIONALLY difficult for an international student to get accepted to medical school in the US? There are only a small handful of international students at medical schools in the US, and most of them come from Canada (the US and Canada share a system for accrediting medical schools).
Biomedical engineering would be easier for an international student to get into. However, there is still the issue of being expected to return to your home country after graduation. Getting a visa to stay and work in the US is generally tough, is a political issue, and what the political situation will be in four plus years is impossible to predict.
What country are you from? What are your high school stats (eg, unweighted GPA, ranking compared to other students in your school, test scores, …)? What is your budget? Why do you want to come to the US to study?