Teens can get free or low-cost STI testing at Title X family-planning clinics, federally funded community health centers, health departments, and Planned Parenthood. Most charge nothing or use an income-based sliding scale, and many serve minors confidentially. Most tests need only a urine sample, a self-collected swab, or a quick blood draw. get tested to start.
| Item | Days after exposure |
|---|---|
| Chlamydia / gonorrhea (NAAT) | ~14 |
| HIV — NAT | 10–33 |
| HIV — antigen/antibody | 18–45 |
| HIV — rapid antibody | 23–90 |
How does STI testing actually work?
Most STIs are caught from a simple sample. Chlamydia, gonorrhea, and trichomoniasis are detected with a urine cup or a self-collected swab run through a NAAT (a nucleic acid amplification test), while HIV, syphilis, and hepatitis are checked with a quick blood draw CDC, HIV Testing. A NAAT amplifies tiny fragments of the bacteria's or parasite's genetic material until there's enough to detect, so it can find an infection from a urine sample without anyone touching you.
In practice it's fast. You'll spend minutes in the chair, pee in a cup, swab yourself in a private room, or hold out an arm for blood, and results typically come back in a day or a few. For chlamydia and gonorrhea, the self-collected swab is just as accurate as one a clinician takes, so many clinics let you do it yourself.
Many STIs cause no symptoms at all. You can carry chlamydia or HIV for months and feel completely fine. Testing is the only thing that tells you your status, and screening on a schedule catches silent infections early, long before anything hurts.
When should you test after a possible exposure?
Every test has a window period, the gap between exposure and when an infection becomes detectable. Test inside that window and you can get a falsely reassuring negative: the infection simply hasn't built up enough yet to be seen. Testing too early is the most common reason for a false negative.
For chlamydia and gonorrhea, a NAAT is generally reliable about two weeks after exposure USPSTF screening. If you need answers sooner, get tested anyway, then retest later when a recent exposure is on the table so an early negative doesn't lull you into skipping follow-up.
HIV is different because the window depends on which test you take. The table below shows the ranges:
| HIV test type | What it looks for | Detection window after exposure |
|---|---|---|
| Nucleic acid test (NAT) | The virus's genetic material | About 10–33 days |
| Antigen/antibody lab test | A viral protein plus antibodies | About 18–45 days |
| Rapid antibody test | Antibodies only | About 23–90 days |
A rapid antibody test is convenient but has the longest window, so a negative soon after a high-risk exposure may need repeating. For a full breakdown of timing by infection, see when to test after exposure.
Where can teens get tested, and what does it cost?
You're rarely far from affordable testing. The US has roughly 16,000 federally funded community health centers and about 4,200 Title X family-planning clinics, plus tens of thousands of other public STI clinics HRSA Find a Health Center. Most offer free or income-based sliding-scale care, which matters a lot if you don't want to bill a parent's insurance.
- Title X family-planning clinics are funded specifically to provide confidential reproductive and sexual-health care regardless of ability to pay; teens are explicitly covered, and fees are based on income, often nothing.
- Federally qualified health centers (FQHCs) use a sliding scale tied to your household income, so the visit costs what you can afford, sometimes a token amount.
- Local health departments frequently run free or very low-cost STI clinics, especially for chlamydia, gonorrhea, HIV, and syphilis.
- Planned Parenthood offers testing on a sliding scale and is experienced with minor confidentiality.
- At-home and self-collection kits let you swab or collect a sample privately and mail it in. Mind the window period so you collect at the right time.
Want to weigh mail-in kits against a clinic visit on price and turnaround? You can compare testing providers before you commit. A clinic that can treat you on the spot saves a second trip if a result comes back positive.
How accurate are the results, and how do you read them?
NAATs are the most sensitive tests for chlamydia and gonorrhea, which is why guidelines name them the recommended method. Modern NAATs are highly accurate, with specificity around 99% CDC chlamydia guidance. High specificity means a positive is very rarely a false alarm. A negative is trustworthy too, as long as you tested after the window closed.
HIV and syphilis are handled with a deliberate two-step process to guard against false positives: an initial screening test, then a different confirmatory test, and the result isn't final until the confirmatory step agrees CDC syphilis lab recommendations, 2024. A reactive rapid HIV test is a preliminary result that must be confirmed with a follow-up lab test before it means anything definite. If you get a reactive rapid result, don't panic; it's a flag to confirm.
If your test fell inside the window, repeat it after the window closes rather than trusting an early negative. For the full science on detection timing, read how accurate is std testing during the window period?.
What if a result is positive?
Most STIs are curable or manageable, and treatment usually starts the same day a diagnosis is confirmed. See get tested for next steps and how to connect with care.
When should you see a clinician?
Get checked promptly if you have symptoms: unusual discharge, burning when you pee, genital sores or warts, pelvic or testicular pain, or a rash. But don't wait for symptoms. Because so many infections are silent, routine screening after a new partner, after unprotected sex, or after a partner tests positive is the standard of care even when you feel fine.
See a clinician sooner rather than later if you've had a known exposure to HIV, since some prevention options are time-sensitive, and if you're pregnant or think you might be, because untreated infections can affect the pregnancy.