Short answer
It depends on the infection. Each one has a window period, the time between exposure and when a test can reliably detect it. Testing too early can give a false negative. Tell your clinician or clinic when the possible exposure happened, and they'll advise which tests to do now and whether you should come back for a repeat test later.
Read the full guideSafer Sex Basics: Condoms, Toys and STI Prevention GuideSafer sex basics made simple: how to use condoms and lube correctly, share sex toys safely, prevent STIs, get tested, and know when to see a clinician. Updated November 9, 2026 · All questions
