I just saw on my medical charts that I was positive for HPV but my doctor never told me, what do I do?

It may be malpractice for the doctor to have not told you, if a reasonable doctor would have (i.e. if the generally accepted standard of medical care would have been to tell you). However, even if it was malpractice, you can only recover for actual losses, injuries, costs (such as additional medical costs), etc. which you have incurred. Therefore, while if you have suffered some actual injury or cost due to the failure to notify you, you would seem to have a valid lawsuit, if you have not actually suffered any injury or loss, there is nothing to sue for, and no point in bringing legal action.