I'm not sure what you mean by "upper line" of your pubic area, but it sounds more like a pimple or hair follicle than herpes.
If you get another one, do not pop it, and get it checked by a doctor within 48 hours of it appearing. If they think it's herpes, insist that they do a type-specific culture or PCR swab on it.
If you think it looks like a pimple, it probably is just a pimple.