If you're planning on starting med school right after undergrad, you'll have to take your MCAT between your junior and senior year. Before you do that, you should have in (at a minimum) bio, g chem, o chem, and physics. So, if you are taking g chem your freshman year and avoid doing bio and o chem together, you're going to have to take one of them together with physics your junior year. I also go to a small liberal arts school with an insanely difficult o chem teacher (who happens to teach like every other bio course in addition to o chem); it is completely doable to have multiple sciences together if you make sure only one is with the difficult teacher.
Other things to keep in mind:
Sometimes bio is a requirement before you take o chem (or you have to at least be enrolled in both simultaneously).
If you're a science major (I don't think you said whether you were unless I missed it), you're going to be cramming a ton into your last two years. Most pre-meds (as stated above) take two to three sciences most semesters (especially if you don't want an awful schedule while you're applying to med school senior year).
