Hi b-real,
Do you know any upperclass pre-meds to whom you can talk, who've taken such a class combination in the past? As others have mentioned, how difficult the schedule will be depends heavily on the structure of both classes at your university. Also. . . how comfortable do you feel with the sciences? Did you struggle in general chem, or in other science courses you've taken? That should help you gauge whether or not it will be too much work to handle gracefully. I've taken some pretty killer courses simultaneously...e.g., one semester junior year I took a three-credit Analytical Chem Lab, 3.5-credit Biochem, and calculus-based Chemical Thermodynamics and Kinetics...but I was a junior Biochem major, so I had adjusted to the rigor of science courses at my college by then.
A lot of premeds have to double up on courses for at least one year. I took chem & physics (& then organic & physics) together...others have taken the chemistry sequence by itself, then doubled up bio and physics. It really depends upon how comfortable you feel with such classes. Also, how difficult will the remainder of your classes be? Are there other courses about which you're concerned? In addition...do you work, or are you deeply involved in extra-currics? It's difficult for anyone here to give you a concrete answer, because just knowing "ochem and physics together" doesn't tell us anything else about your schedule, in terms of its flexibility.
So to make a very long-winded post...well, still long 🙂 , talk to others at your college, and then think about what else you have planned for next year, and how much time you predict you might have to devote to the classes. Good luck!!! 😀