You should always go to a doctor with your first possible yeast infection. There are several things it could be besides a yeast infection--bacterial vaginosis among them.
Once you are over 18 and/or sexually active, you should be going to the gyno once a year anyways. Annual exams are far less scary than people make them out to be. While uncomfortable, certainly, there are much worse things to be faced in life, and putting your health at risk instead of facing a little discomfort is not the best thing to do.
Find a good doc and you'll be fine
