If you don’t have symptoms but are sexually active you could have an STD and should consider getting tested. You need to be tested anytime you have symptoms which include but are not limited to:
Discharge from your penis or vagina
Blisters or warts on your genitals
Burning when urinating
Abdominal pains
Bleeding from the vagina between periods
Once you have been tested you should get retested anytime you:
Have had sex with a new partner since being tested
Have had sex without a condom
Have had sex with multiple partners
AND any time you have symptoms.