Very common. It is still very unlikely you have either of these infections, but testing is the only way to know for sure.
Feel free to return to let me know the results if and when you get tested. You can expect all of them to be negative. Until then, I won't have anything more to say.
How common is it for hsv and syphilis to not show symtoms for two years?
I meant to note that you don't mention the sex of your partners. If you have sex with men, especially in casual relationships, your STD risk is higher, and HIV becomes a more likely concern. However, my reply still stands: get tested, then relax and stop worrying about STD if/when you receive the negative test results.
Welcome to the STD forum.
First, you really aren't asymptomatic, since you describe symptoms that concern you. But you appear to understand that they are not the symptoms of any STD, including all the ones you mention. Second, you have had a pretty conservative sexual life. Most people with only 6 lifetime sex partners don't catch STDs except for HPV (discussed below) -- although this of course varies with the nature of your sexual partnerships. If any partners were commercial sex workers, bar pick-ups, or similar casual partners, the risk of course is higher.
It is exceedingly unlikely you have had gonorrhea or chlamydia for more than 2 years; most cause symptoms (discharge of pus or mucus from the penis) within a few days of onset, and all infections clear up on their own within that time. In the pre-antibiotic era, most gonorrhea in men was believed to self-cure in 6-12 weeks. Chlamydia can persist longer, but has never been shown to persist 2 years in men.
Most genital herpes infections are asymptomatic, and syphilis can go for years without symptoms. And most HIV infections are asymptomatic for many years before symptoms of AIDS appear. Finally, most people catch one or more genital human papillomavirus (HPV) infections within their first 3-5 sex partners, so you can be quite certain you have been infected at one time or another with HPV. But the large majority of infections remain asymptomatic and clear up on their own within 1-2 years.
To settle your concerns, see a health care provider for STD/HIV testing. Your local health department STD clinic (GUM clinic in the UK, sexual health centre in Australia, etc) would be an excellent source. A urine sample can be tested for gonorrhea and chlamydia and blood tests for HSV, HIV, and syphilis. (There is no test for HPV, but it doesn't matter.) Most likely all will be negative.
Whether or not your tests show anything, it won't explain your symptoms. As I said above, they do not suggest these or any other STD. If they persist and you remain concerned, discuss them with your primary health care provider.
I hope this helps. Best wishes-- HHH, MD