the most likely reason is that one of your previous sexual partners has not experienced the hpv infection (most women don't) and if you're not looking for them (regular physicals) there can be some that small that your doctor wouldn't see them with his/her eyes only. there is a tiny tiny chance that you had a wart on your hands or some other part of the body that you cut and then spread the virus to your genitals (the doc told me that he sees this pretty much only when women shave and spread the virus with the razor because both sites have miniscule nics). but this is so unlikely that i would say it has to be your partners.
causes of genital warts without sex? . i'm a male and i went into the doctor's to see about what i thought was acne around my genitals (just above my penis). he told me it was warts caused by hpv and despite me practicing safe sex a condom doesn't protect against it. but i've contacted my previous 4 sexual partners. in the years since we've been together they've all been tested for different reasons: pregnancy cancer abortion and regular physicals. . how else could i have gotten them?