What if I have been vaccinated with bcg?

Same TB testing. In the United States, PPD skin testing is done when needed, regardless of whether a person had a BCG shot in the past. If a person had a positive skin test in the past, then his doctor may skip doing a PPD test, and just check a chest x-ray and a blood test. Many people with past BCG shots do not have positive ppd's when tested years later by their doctors.
May have (+) PPD. In the future you may be screened for tuberculosis with chest xray since regular TB testing may show a false positive.