You can’t tell if you have an STD just by the way you look or feel — most of the time, people with STDs don’t have any symptoms. So the only way to know for sure if you (or your partner) have an STD is to get tested. It’s extra important to get tested if you’ve had unprotected sexual contact, or if you find out your partner has an STD. A doctor or nurse can tell you whether or not you should be tested for STDs. If you DO have an STD, it’s best to find out as soon as possible. Some STDs can cause serious damage over time, even if you feel totally fine right now. STDs can also spread to other people you have sex with, whether or not you have any symptoms.