Im not sure if i have it or not?

Hey, im a college student, who had unprotected sex with my girlfriend numerous times. A couple of nights i got lazy and fell asleep with cleaning up. The next day i had these what looked like warts on my skin. So i went to the clinic for a test. My doctor told me it looked like HSV2. So she did a test for it and a week and a half the test came back neg. They said to call if i ever got another break out. Well that was like 3 months ago and the break out finally completely went away. They said i might need to talk to a dermatologist. So heres my ?. Is it possible for the herpes virus not to show up in a test but still be there? thanks a lot.