Does it look bad on your application if you only take three science classes in high school if you are not majoring in a field that requires a science?

No it is not bad if you do so because it does not matter since you are majoring in something else. Most colleges only require 2 or 3 science classes to get into the college. Since you are not majoring in science related field, you are fine taking just enough to get in. Another thing that might help you is if those 3 classes that you took were some of the more challenging classes. 3 years of the harder science classes might mean more than 4 of the easier ones.