What classes should I take?

I'm a biology major, and the next line up of pre requisites I need is Physics I, General Chem II and also Calculus. I'm a bit apprehensive about taking physics and calculus, or all three of these classes, together in the same semester. However, I need to take at least 12 credits in a semester to keep my full time status, so even if I only took two of these classes (4 credits each) I would still need to take two other classes that are three credits each to have a total of at least 12 credits. Should I just take all 3 together or take 2 and then 2 other general ed classes?