I think at this stage I would look to major in something that interests you and give you a degree you can immediately apply upon graduation (e.g. computer science) but take all the pre-med classes to keep that option open. But also, talk to people in the field, find out what they like/don't like and if they had to do it all over again, what they would do.d In the end though, it's really hard to optimize any given career path so don't put too much pressure upon yourself if you feel like you don't have a clear idea of what you want to do, just keep exploring as much as you can. As for what to do if your startup fails, you would either start another or get a job.
