This is what was recommended to me by an advisor once.....

Is it possible to take a class in some of the other degrees/majors you are in interested in before making the change, or are you required to be in the that degree plan before you can take specific classes? I know some colleges do require that, others you can take whatever classes whenever. If whenever, add one into to your base of core classes to try one out in the new field you are interested in and see how it goes, how you like it. That way you are still getting your core classes that fit for any field to make progress and can also find out if there is something else out there for you that you like better.

If you have to be in the particular degree plan, talk to someone in the department to get more information about the field and classes; if still interested, see about changing. It is an easy process that can be done at any time most places.