Assuming you are roughly over the age of 12, you are defined as an autonomous individual, and thus you are protected by the right to patient confidentialliy. It is your doctors medical & ethical duty to protect this right, even withholding this information from inquisitive parents unless you give him explicit permission to share the information. The only exceptions to this rule would be if you were not considered an autonomous individual (eg. retarded/mentally incapacitated), had appointed your medical rights under court approved power of attorney, or if the results/treatments would subject you to outcomes that you are incapable of fully comprehending at your stage.
In other words, the doctor is bound by the Hippocratic oath NOT to divulge any personal/confidential information to anyone but yourself. If he does not respect this right, you could lodge a complaint with the american college of physicians and have his license revoked.