How can I tell if I have asperger's syndrome or am just shy WITHOUT being diagnosed?

There's no real difference between Asperger's Syndrome and having these traits. The only difference is whether you have a diagnosis or it. Keep in mind that autism is a classification invented by people, it's not an absolute thing you either have or don't have. If people are prejudiced, it may be best not to say it, especially if you don't really have a disability. You don't need to make excuses though, you are who you are.