when i was very active ... i would have a test quarterly.
are you in Japan? there are clinics that specifically just do STD testing. so you don't mingle with a large crowd.
things to ask yourself
- do i have possible symptoms (like for example strange/foul things comming out out of urethra, pain in peeing)
- do i have sex (protected or unprotected) w/ anyone (relationship/partner or p4p )
yes to both?? go have a test. depending on your situation and frame of mind, yes to any should prompt you to go have a test.