Chlamydia is called the silent epidemic, it has almost zero symptoms,
it will eventually make you sterile, syphilis, can have effects like Kaposi's Sarcoma,
Gonorrhea can have discharges, when not doing anything, the way to know is to go to the doctor, STD's never go away on there own, some are treatable some are permanent,
and you shouldn't be having sex with every person you meet, and always, always wear a condom!.
You could, and the only way to know is to get tested.
Aj