Are they at all willing to talk about it? When I first told my mother I suspected I had AS, she said, "Oh, no you don't, you function much too well." However, a few weeks later she called me up and said, "When you mentioned having Asperger's, I blew you off, and that was wrong of me. Can you tell me more about why you think you have Asperger's Syndrome?" So I did, and she came around to my way of thinking and encouraged me to get diagnosed. (When she told my father, he simply said, "Yes, I've thought so for a while.") I got diagnosed a bit after that, and they have been nothing but supportive. Perhaps you could try to explain to your family why you think AS is you, before you seek a diagnosis?