If you have never had sexual contact of any kind with another person, there is no risk of STD/STIs. But if you or your partner has ever had sex with anyone else, then testing can help you learn whether you may have contracted an STI. You can’t rely on symptoms to know whether you have an STI—many STIs can be “silent,” causing no noticeable symptoms. Also, some STD/STIs may not be detectable through testing for anywhere from a few weeks to a few months, so talk to your healthcare provider about the right time to get tested.