http://www.ou.edu/admissions/academics/medicine/pre-medicine.html
Program Description
Second paragraph reads in part “Students may major in any academic area as OU undergraduates, as long as they take the pre-requisite pre-Med courses…
If anything you may want to consider an academic area that interests you as if you like material you’ll tend to do better. In addition you may want to consider a major which can serve as a Plan B should you change your mind about medicine. Engineering tends to be a difficult major to maintain a competitive med school GPAs.
Although premed reqs can vary from school to school, use link below to OK’s med school’s premed reqs as a starting point to see what you may be facing. Many students will choose Bio as a major, perhaps out of interest, but also because of course overlap (you satisfy both premed.major reqs at same time) where if you’re say a history major, you have to find way to schedule in premed reqs.
https://www.oumedicine.com/college-of-medicine/information-about/admissions
The most important thing you can do now is continue to strengthen your academics and enjoy remaining time in hs. Good luck.