What grade are you in-- are you a senior? U.S.? I'm going to assume that you are in the U.S, applying to schools in the U.S., and your school offers AP courses and you decided not to take them-- no university will penalize you for not taking them if they weren't offered. What types of colleges are you hoping to get into? I'll bet there are plenty that would give you a great education that aren't terribly selective, but for those that are very selective, they really want to see students taking a rigorous courseload each year. Calc III helps, but more so at some schools than others. For schools you're interested in, search "[school name] common data set" (or CDS). Once you've found that, look for a chart that indicates which factors are most and least important for admission to that college. You can see how rigor of course load compares to all the other factors.