Accent question? United States

Quick question about accents and if they can differ or even change. I was born and raised in Michigan and currently live in Michigan, and so do my parents and immediate family. My family has the typical Michigan/midwestern accent. Mine, however, is slightly different I have been. People have asked me If I grew up in the south because they say I sound different and slightly southern. I have never actually paid attention to how I speak until recently and I can hear it. What causes this? Has this ever happened to anybody else?