how did you know ...

how did you know you had genital herpes ?? I got the swab test before ( negative ) and the doc said it didn’t look like it but every since then I worry myself sick and now I have a spot down there but I shaved two days ago so it could be ingrown because I am prone to get ingrown hairs.. But if you don’t mind you comment please tell me how did you know you have Genital Herpes??