You can really major in anything and go on to medical school. You’ll just need to take sufficient science and math courses to do well on the MCAT test. Oklahoma or any other school you attend will very likely have pre-med advising to help you determine the classes you need to take to prepare yourself for the MCAT. To emphasize, though, you can major in bio, chem, biomedical engineering, physics, math, anthropology, econ, or most anything else. The important thing is to do well in your classes and take the classes that prepare you for the MCAT. Also, med schools now want to see applicants have a lot of hands-on experience. They look for many, many hours of service work, including some in medical-related fields. One of the best things you could do to prepare yourself for med school is to get EMT certified and volunteer while in college. You can probably take the course necessary for certification in college, or even perhaps at a community college or other location before you go off to college. There are certainly other things you can do as well. This is just one recommendation. You can search the University of Oklahoma site for pre-med advising. You might even find a list of recommended courses or a recommended schedule for pre-med students. Good luck!