Can the gyn doctor see if you have any STDs from looking at your vaginal area when he does the pelvic exam?
Sometimes. There are some std's that cause vaginal discharge that can be quite distinctive on examination but usually you need confirmatory tests by looking under a microscope or doing a lab test to be sure. Some std's dont have any signs or symptoms in girls and the only way to diagnose them is to do a routine screen. For example gonorrhea and chlamydia are tested routinely in girls under 25 due to risks.