If you’re reading this article, it’s likely you’ve just enjoyed, or maybe not really enjoyed (depending on your perspective), a sexual encounter with someone. Pleasure aside, you probably want to get tested right away to make sure you haven’t contracted anything from them, and that’s understandable. Even as someone who already has one STD (herpes), I would prefer to avoid contracting additional STDs, if I can help it. So knowing when to get tested after a possible exposure is important because I want to avoid an inaccurate result and having to take a lot of re-tests.
Unfortunately, the question of when to get an STD test is not as easy to answer as you might hope, because STD testing is not a perfect science. Most people want to get tested sooner rather than later, and time is not really of the essence, when it comes to STD tests. The longer you wait, the more likely you are to have an accurate result. And even if you have, theoretically, waited long enough for a test to work, you could still end up with a false positive or a false negative.
Then, you need to account for the fact that not all STD tests work in the same way. Some tests look directly for the presence of a pathogen (like chlamydia or HIV, for example), and others look for your body’s immune response to the infection (antibodies that fight the infection). Tests that look for the pathogen themselves are more accurate than the tests that look for your body’s immune system response, but most people don’t know which tests they’re being offered.
Finally, the timing for infections to show up on a test vary. The two terms you need to know when figuring out when to get tested are incubation period and window period. The incubation period is how long it takes after getting infected to show signs and symptoms of an infection. The incubation period is important for infections that are diagnosed via visual symptoms and not through a lab, like molluscum contagiosum or pubic lice.
If you have signs or symptoms – anything that is abnormal for you, from discharge to bumps, then go to your provider right away and have them check out your symptoms. If you don’t have any noticeable changes, then you’ll want to wait to get tested during the appropriate STD testing windows. The window period is the time it takes from contracting an infection to when it will show up on a laboratory test.
Testing for Antibodies
Tests that look for antibodies don’t require a doctor to know where to sample (for instance a swab of the throat vs a swab of the anus), but the tests take time to turn positive. That is because your body’s immune system must first react to the infection and then produce detectable levels of antibodies for a test. Different types of antibodies peak at different times after infection, and so the window period from one infection to another can be very different.
In some cases, a positive antibody test can be used to determine how long you’ve been infected with an STD. For example, a positive antibody test for hepatitis A would indicate you’ve had the infection for a least 2 weeks, or maybe longer.
However, the body’s delayed response to an infection – the window period between the time of infection to the time it takes the body to develop enough antibodies to show up on a test – also affects how long it takes for a test to become reasonably conclusive.
Testing for the Infection
On the other hand, tests that look directly for the pathogen often become positive faster, since pathogens are there from the start of the infection, but some of those tests require samples from an infected location to work.
For example, new tools have allowed doctors to use urine testing to look for chlamydia and gonorrhea bacteria, but urine tests only determine genital infections (penis or vagina) and a swab would still be needed to detect an infection in the mouth, throat, or anus.
If all of that sounds overly complicated, it’s because it is.
Being able to definitively answer when you will test positive or negative on an STD test after a sexual encounter requires knowing a number of things including: what sexual activities happened, what STDs the person has been exposed to, and what tests were being used to detect the infection. That’s why the Centers for Disease Control (CDC) recommends certain tests at certain ages and based upon a list of risk factors.
Determining the accuracy of STD tests from exposure to window period all the way to incubation period is even a difficult question from a research standpoint – how do you ethically expose someone to an STD and then repeatedly test them to determine how long it takes for them to test positive? Because of this, there are very few resources that can tell you exactly how long after an exposure people should wait to get tested for many of the 30+ STDs out there.
But you can still proceed responsibly under some basic guidelines.
A General Rule of Thumb
In general, you can go in for basic testing for some common bacterial STDs (chlamydia, gonorrhea, and syphilis) as soon as 2 to 3 weeks after an exposure, and even sooner if you have symptoms. If you have symptoms, then go in right away, regardless of incubation or window periods.
Your testing provider might also offer some additional tests at that point, like HIV or hepatitis C, and there’s no harm in saying yes to those tests as well.
No matter the outcome, you will want to be retested again at least 3 to 6 months later in order to feel relatively certain of your results.
Considerations During and After Testing
If you were recently tested, and you’re waiting for conclusive results, you’re probably wondering, “do I have to tell current or future partners that I might have an STD?” And maybe you’re also thinking, “what if we only had/have oral sex?” or “what if it didn’t/doesn’t last long?” While all of those are valid questions, ethically, STD testing and safer sex conversations should happen at every level and with all of your partners.
The choices you and your partner(s) make about your bodies, acceptable risk, testing, and safer sex have to be completely consensual at all times.
Remember, most people don’t come to sexual relationships completely inexperienced, so talks about testing and safer sex are always good ideas for everyone, despite how awkward they feel at first. During the testing process, you can discuss safer sex methods with your partners, until you are reasonably certain of your test results, and afterward, you can decide together if and how you’d like to prevent new infections.
The question of disclosure is certainly more complicated if you’re already sexually involved with someone, but the discussion is still important because it gives a partner the chance to minimize their emotional and physical risk. Although people have certainly used it as a tool of manipulation, having an STD does not make you damaged or unworthy of a healthy relationship, and no one should stay in a relationship that does not respect their overall health and well-being.
Fortunately, once most people get past the initial shock and the stigma of an STD diagnosis, they realize that an STD isn’t the end of dating, a great sex life, and healthy relationships.