<p>Since pre-med is a track, majoring in something else is definitely possible, and I think a backup plan is very smart. I know some people that majored in things like English or Classic literature (gives great essay writing skills) and made it into med school. If you do decide on CE or CS, try to fill some elective space with bio and chem courses not necessarily required for admission to med school.
Also, do you actually like these CE or CS? Could you see yourself in these fields? Are you currently in college?
Keep in mind that engineering curriculum is usually very rigorous and can result in a lower GPA which can damage med school admission chances.
You should talk to an academic adviser to see if the prerequisites and a few electives fulfill a bio or chem major/minor. That might also ease your mind.
I hope this helped you 
Best of luck. Try these sources as well:</p>
<p>[Choose</a> the Right Undergraduate Major for Medical School - Medical School Admissions Doctor (usnews.com)](<a href=“http://www.usnews.com/education/blogs/medical-school-admissions-doctor/2013/09/11/choose-the-right-undergraduate-major-for-medical-school]Choose”>http://www.usnews.com/education/blogs/medical-school-admissions-doctor/2013/09/11/choose-the-right-undergraduate-major-for-medical-school)
[Pre-Med:</a> A 4 Year Plan<a href=“they%20have%20a%20four%20year%20plan%20that%20you%20could%20follow%20even%20if%20you%20aren’t%20a%20bio%20major”>/url</a>
<a href=“http://talk.collegeconfidential.com/high-school-student-topics/481767-engineering-majors-premed.html[/url]”>http://talk.collegeconfidential.com/high-school-student-topics/481767-engineering-majors-premed.html](<a href=“http://www.georgetowncollege.edu/bio/student-resources/planning-and-scheduling/pre-med-a-4-year-plan/]Pre-Med:”>Four year plan for medical school | Georgetown College)</a> </p>
<p>I hope I was able to help!</p>