If you want a "backup plan", apply to graduate school. I did this (year's ago) and even though I never thought I'd "use" this option, I ended up getting a master's degree. No one is going to fault you for applying to graduate school at the same time as medicine. If it comes up, you can explain that you want to continue your education, while still trying to increase your chances of getting into medicine when you were through with your graduate degree (assuming, of course, you don't get in the first time). Adcoms won't think you're confused or a flake for coming up with a backup plan that involves graduate school. The only time this is a problem, is when you apply to medical school in the middle of a graduate program. Then they make you show proof that your graduate committee knows you're applying, and that you'll be through with your program before you start medical school. Otherwise, applying to both programs is not a problem.
