I changed my major when I was in my 3rd year at university (1970) got my degree in my new subject and then went back in 2001 and started studying to get another degree in my original subject (which I did in 2007). I'm now doing advanced schooling in my original subject still but it very neatly ties together both subjects.

You cannot ever know the future; what will happen, what you will enjoy, what you have learned that will be most useful even. If I had to do it all over again, I would pay more attention to what I wanted at the time and not try to second guess the future. My work life and schooling all played out wholly different than I "thought" but came out fine in the end. When I was 20 I did not have much education and no experience in the world; now I am over 60 and have both and great hindsight about how it all works together :-) I would follow what you want; whatever you do, I believe it will work out okay in the end.