Anyone tested positive for herpes? How do they test if you aren’t currently having an outbreak?

I’m 20.5 weeks pregnant, I’ve been tested for everything, but herpes by my ob.. all negative. They won’t test me for it because I’m not having an outbreak (I have had tiny sores pop up down there and go away the past year or so, so I’m 99% sure I have it.) I made an appt at a planned parenthood near me to get tested.. how do they do it?