Can I work as a RN with a Misdemeanor conviction?

I am continuing my education in hopes of attaining a ADN. (Associates Degree in Nursing) What is the likelihood/unlikelihood of landing a job? The conviction is over 6 years old. It was for theft under $500. I have not hired an attorney yet to have it expunged, because im not sure what good it will do.They say some people(schools, hospitals) will still be able to see the record. Doesn't it "expire" after seven years anyway? This was my only arrest, only conviction, and no drugs were involved. I was 20. I hope it doesn't ruin the rest of my life. I've grown up a lot. Thanks for input!