One of my professors got an MBA and then started a psych PhD program. Another was a psychologist and then got an MBA to help with managing the clinic he ran. One of my classmates in my master's program in counseling was a lawyer. Another was a high school principal. People do get into psych programs from a variety of backgrounds.

If you haven't taken a lot of psychology, you might want to pick up some classes, do some volunteering, and get involved with a research project somewhere. It seems to be getting more competitive all the time. I'd still like to get a phd and be a psychologist, but don't know if I can get in, and I have a 3.96 GPA and some clinical experience. I've been turned down several times. Not enough research experience. But it might be easier to get into a research degree program since there is often more demand for clinical.