Hello. Thanks for writing to us at healthcaremagic Herpes does nt necessarily have to be a recent infection for it to cause sores. Now that a lab test has revealed it that you have the infection, it is possible that you probably had it already from your previous sexual encounters and the episode which you have right now is just a recurrence (recurrent genital herpes). Since your present episode was a short lasting one and not a florid one; this is another point that goes in favor of a past infection; first episodes of herpes is usually very painful with multiple sores and can last for 2-3 weeks. Recurrent episodes are short lasting. Herpes once acquired stays in the system throughout the life and may cause recurrences which may occur at varying frequencies. Herpetic sores are fairly distinctive to be missed or confused with something else. Therefore, I would suggest that if in case you develop sores sometime again you should visit a specialist for a physical. Regards