For a patient who presents after an episode of unprotected sexual intercourse, seeking testing for STIs, it’s important to know when to perform the test. The time between infection and a positive test is called the testing window. This testing window can be different for different pathogens. In this episode, we will review the importance of knowing this testing window, and we will also review the differences between pathogen inoculation, incubation/latency, and their overlap with the testing window.