Below the neck - do you mean on the genitals? If so, no. Herpes infects nerve groups. Genital herpes infects the sacral ganglia, which affects the area covered by boxer shorts. It can't travel outside that area. Oral herpes infects the trigeminal nerve, which affects most of the face. It can't travel outside of that area.
You can, however, autoinoculate, which means infect yourself in other areas. If you have a sore on your genitals, and touch it, and then touch your mouth, you might infect your mouth. This isn't common, though, and it would happen before you have antibodies that protect you from doing so.
Antibodies develop in as little as 10 days, and can take up to 12 weeks. If you've tested positive on a blood test, you have antibodies.
You could have also been infected at the same time. If you got genital herpes from oral sex, and you kissed that person, you could have gotten oral and genital hsv1 at the same time.
You wouldn't get it on your arm, leg, back, etc.
Is that what you meant? If it's not, and you have more/different questions, let us know.