Misdiagnosed with Asperger syndrome

Hello. I was misdiagnosed with Asperger syndrome when I was fourteen years old. This has never really been a problem before, but I've recently graduated from university, and I'm concerned that it could become an issue. Firstly, I will soon have my own health insurance, and this diagnosis could possibly increase the amount I have to pay. Secondly, I'm applying for higher-profile jobs now that I have a college degree, and some of these may conduct more extensive background checks, which could possibly include mental health. Third, I just don't like having it "on record" that I'm autistic when I'm not.

Anyway, my question is this: how would I go about being "undiagnosed?"

By the way, I live in California, if that makes a difference.