Usually they ask you because it costs more (although
insurance usually covers). Swabs only
test for HPV, gonorrhea, and chlamydia to my understanding. Herpes, syphilis, and HIV are all blood tests unless you have a lesion. If I were you, I would call your doctor; they should have on file what you were tested for, when, and the results. Pap smears and annual exams do not ensure that you've had STD testing.