How Long After Unprotected Sex to Get Tested
How long after unprotected sex to get tested depends on the infection. Test for chlamydia and gonorrhea about 2 weeks after sex; a test before that can miss the infection. Blood tests have their own timing: HIV tests take about 10 days to 3 months depending on the test, and syphilis and hepatitis B can take weeks to show.
If you have symptoms, see a doctor without waiting for the window period (CDC). If there is any chance of HIV, ask about PEP today. It has to start within 72 hours (CDC).
How Long After Unprotected Sex to Get Tested: STD Testing Timeline
A window period is the time between exposure and the day a test can find the infection (CDC). Every STD test has one, and a test taken inside it can come back negative even if you are infected.
The chart below shows when to get tested after unprotected sex: the STD window period for each test. It uses CDC timing where CDC gives one. For chlamydia and gonorrhea, it uses UK guidance (BASHH) and StatPearls (NIH).
| STD | Sample | Test timing after sex |
|---|---|---|
| Chlamydia | Urine (men) or vaginal swab (women); a rectal swab after anal sex | Test about 2 weeks after sex. A test in the first 2 weeks can miss it (BASHH, UK) |
| Gonorrhea | Urine (men) or vaginal swab (women); a throat or rectal swab after oral or anal sex | Test about 2 weeks after sex. A test in the first 2 weeks can miss it (BASHH, StatPearls) |
| Trichomoniasis | Vaginal swab or urine | No set window in CDC guidance. If a first test soon after sex is negative and you weren't treated, STI tests can be repeated 1 to 2 weeks after the exposure (CDC) |
| HIV | Blood | NAT (looks for the virus itself): 10 to 33 days. Lab antigen/antibody test (looks for a piece of the virus and for antibodies): 18 to 45 days. Rapid finger-stick antigen/antibody test: 18 to 90 days. Antibody test: 23 to 90 days (CDC) |
| Syphilis | Blood, or a swab of a sore | Antibodies might take up to 2 weeks to develop after primary infection, and blood tests might not yet be positive in early syphilis. A negative test in the first weeks can't rule it out (CDC) |
| Genital herpes | Swab of a sore; blood test | Swab: when a sore appears. Blood test: can miss a new infection; repeat it 12 weeks after the exposure (CDC) |
| Hepatitis B | Blood | As early as 1 to 2 weeks, as late as 11 to 12 weeks (CDC) |
| Hepatitis C | Blood | Virus (RNA) test: 1 to 2 weeks. Antibody test: on average 8 to 11 weeks (CDC) |
| Mycoplasma genitalium | Urine or swab | No set window. CDC does not recommend testing people without symptoms |
| HPV | — | HPV tests are not recommended for men (CDC) |
Sources: CDC; BASHH (UK); StatPearls (NIH). Full list at the bottom of the page.
How Long Does It Take for an STD to Show Up? STD Incubation Period vs Window Period
It depends on what "show up" means: symptoms appear after the incubation period, the time from exposure to the first symptoms (CDC), while a test turns positive after the window period. The two are not the same, and many people with an STD never have symptoms at all.
| STD | Symptoms usually start (if they start) |
|---|---|
| Chlamydia | May not appear until several weeks after sex, if at all (CDC) |
| Gonorrhea | 2 to 14 days in men, 2 to 10 days in women (StatPearls) |
| Trichomoniasis | 5 to 28 days in some people; others much later (CDC) |
| Syphilis | A sore about 3 weeks after sex, anywhere from 10 to 90 days (CDC) |
| Genital herpes | 2 days to 2 weeks (MedlinePlus, NIH) |
| HIV | Flu-like symptoms 2 to 4 weeks after infection, in about two-thirds of people (HIV.gov) |
| Hepatitis C | 2 to 12 weeks on average (CDC) |
| Hepatitis B | About 90 days on average, from 60 to 150 days (CDC) |
No symptoms does not mean no infection. Chlamydia often has no symptoms (CDC).
About 70% of people with trichomoniasis have none (CDC), and about half of adults with a new hepatitis B infection have none (CDC). That's why the test date matters more than waiting for signs.
The chance of catching an infection from one encounter depends on the infection and the partner. For the numbers, see the chances of getting an STD from one encounter.
How long does an STI take to show in a woman?
Women follow the same testing chart, so don't wait for symptoms to decide. Most women with gonorrhea have no symptoms, and some notice nothing until complications such as PID (pelvic inflammatory disease, an infection of the womb and tubes) develop (CDC).
For chlamydia and gonorrhea, the best sample for women is a vaginal swab (CDC).
How Long Does It Take for Chlamydia to Show Up?
How long does chlamydia take to show up on a test? It may not show up in the first 2 weeks after sex, and a UK patient guide from BASHH says you may be asked to repeat the chlamydia test 2 weeks after the risk. Symptoms, if they come at all, may not appear until several weeks after sex (CDC).
CDC does not give a set number of days for the chlamydia incubation period. Many people never get symptoms, so a test is the only way to know (CDC).
The test is a NAAT (nucleic acid amplification test), which looks for the germ's genetic material. It uses first-catch urine (the first part of the stream) for men and a vaginal swab for women (CDC). If you notice discharge or burning, compare chlamydia vs gonorrhea symptoms.
How long does gonorrhea take to show up?
The gonorrhea incubation period is short: symptoms, when they come, usually start 2 to 14 days after sex in men and 2 to 10 days in women (StatPearls). On a test, the timing matches chlamydia: testing within 2 weeks of sex may miss it (StatPearls, BASHH).
In men, gonorrhea can cause symptoms early enough to get treated, but often not early enough to avoid passing it on (CDC). Gonorrhea in the throat usually causes no symptoms (CDC).
HIV, Syphilis and Hepatitis: Blood Test Timing
Doctors find these infections with blood tests. Many of those tests look for antibodies, the proteins your body makes to fight an infection, and those take time to build. So a single early blood test often can't rule these infections out.
HIV
No HIV test can find HIV right after sex (CDC). The lab antigen/antibody test, done on blood from a vein, usually finds it 18 to 45 days after exposure. The rapid finger-stick version can take 18 to 90 days (CDC).
If your test was negative but done inside the window, test again after the window. A negative test after the window, with no new exposure in between, means you do not have HIV (CDC).
A faster result does not shorten the wait. Our rapid HIV test gives results in 30 minutes, but it is a finger-stick test, so the 18 to 90 day window applies. HIV medicine taken as PEP (after exposure) or PrEP (before sex, to prevent HIV) can also delay a positive result (CDC).
Syphilis window period
Syphilis blood tests can be negative early on. CDC notes that antibodies might take up to 2 weeks to develop after primary infection, and blood tests might not yet be positive in some people with early (primary) syphilis. The syphilis incubation period, the time to the first sore, is about 3 weeks, anywhere from 10 to 90 days (CDC).
So CDC gives no single number for the syphilis window period, and a negative blood test in the first weeks after sex can't rule syphilis out. If you have a sore, the doctor can test the sore itself (CDC). For how the syphilis blood test (RPR) is read, see our page on it.
Hepatitis B and C
Hepatitis B shows up on a blood test for a piece of the virus (HBsAg) as early as 1 to 2 weeks and as late as 11 to 12 weeks after exposure (CDC).
For hepatitis C, a virus (RNA) test can find it 1 to 2 weeks after exposure. The antibody test turns positive later, on average 8 to 11 weeks after exposure (CDC).
Herpes, Trichomoniasis, Mycoplasma and HPV
These four don't follow a simple day count. Herpes is best tested with a swab when a sore appears, and trichomoniasis often has no symptoms, so testing is the only way to know.
CDC does not recommend testing people without symptoms for Mycoplasma genitalium, or HPV tests to screen men.
Herpes
The best herpes test is a swab of a sore while it is there (CDC). A blood test can miss a new infection, so CDC advises repeating it 12 weeks after the possible exposure.
CDC does not recommend routine herpes blood-test screening for the general public. Testing can make sense in some cases, for example if your partner has genital herpes (CDC). More on how to test for herpes.
Trichomoniasis
Most people with trich have no symptoms (CDC), so testing is the only way to know. A NAAT is more sensitive than looking at a sample under the microscope (CDC). For women, we offer a rapid trichomoniasis test.
Mycoplasma genitalium
Mycoplasma genitalium has no official window period. CDC does not recommend testing people who have no symptoms. If you do have symptoms, see Mycoplasma genitalium symptoms.
HPV
CDC does not recommend HPV tests to screen men, and there is no test for a person's "HPV status" (CDC). Doctors use the HPV test only to screen women 30 and older.
Warts or other signs can appear years after sex (CDC). See HPV testing for men.
Is 1 Week Too Early for an STD Test?
For HIV and syphilis, yes. Even the fastest HIV test, the NAT, which looks for the virus itself, usually can't find HIV until 10 to 33 days after exposure (CDC). For chlamydia and gonorrhea, a test at 1 week may find an infection, but a negative result can't rule one out until about 2 weeks have passed (BASHH).
So how soon after unprotected sex can you test for STDs? A test the next day can't be relied on to find an infection from that encounter, for any STD on the chart. It can only find an infection you had before.
Whatever the chart says about how long after sex to get tested, testing early still makes sense in some cases: you have symptoms, a partner told you they tested positive, or you would worry less with a first result. Just plan a second test at the right time.
In my practice, when someone comes in a few days after sex, I test for what can already be found and set a date for the rest.
What to Do in the First 72 Hours After Unprotected Sex
Two medicines have a 72-hour limit: PEP for HIV, and doxy-PEP for some bacterial STDs in people it fits (CDC). Symptoms and a partner's positive result also call for action now, not after the window period.
- If there is any chance of HIV, ask about PEP today. PEP (post-exposure prophylaxis) is HIV medicine that must start within 72 hours (3 days) after exposure. The sooner, the better (CDC). See HIV PEP.
- Ask about doxy-PEP if it fits you. CDC tells doctors to offer it to gay, bisexual and other men who have sex with men, and transgender women, who had syphilis, chlamydia or gonorrhea in the past 12 months. It is a 200 mg dose of the antibiotic doxycycline, taken as soon as possible within 72 hours after sex (CDC, 2024).
- If you have symptoms, see a doctor now (CDC). Don't wait for the window period.
- If a partner tells you they have chlamydia or gonorrhea, get checked and treated now. CDC advises that partners from the last 60 days be tested and treated without waiting for their own results.
At STD Center NY, we prescribe both PEP and doxy-PEP.
When to Retest After an STD Test
Knowing how long after unprotected sex to get tested is half the job. The other half is retesting. Retest in three cases: your first test was inside the window period, you had a new exposure, or you were treated for an infection.
- First test too early. If your first tests were negative and you weren't treated, you can repeat STI tests 1 to 2 weeks after the exposure (CDC). For chlamydia and gonorrhea, UK guidance uses 2 weeks (BASHH). Syphilis and HIV tests need their own longer windows. For HIV, test again once the window for your test has passed (CDC).
- After PEP. CDC advises HIV testing 4 to 6 weeks and 12 weeks after starting PEP.
- After treatment. Retest about 3 months after treatment for chlamydia or gonorrhea, and for trichomoniasis if you are a woman, even if your partner was treated too (CDC).
- Not too soon after treatment. A chlamydia NAAT less than 4 weeks after finishing treatment can be falsely positive, because the test can pick up dead germs (CDC). For trichomoniasis, wait at least 3 weeks (CDC).
Test Every Place You Had Sex
A urine test does not check your throat or rectum. Chlamydia and gonorrhea in the rectum or throat are found by testing that spot (CDC). If you had oral or anal sex, ask for a throat or rectal swab too.
This matters most for gay and bisexual men. Urine or genital testing alone might miss about 70% of gonorrhea and chlamydia infections in men who have sex with men (CDC). CDC does recommend throat testing for gonorrhea, but not for chlamydia.
At STD Center NY, throat and rectal swabs go to the lab. More on STDs from oral sex.
STD Testing at STD Center NY
At STD Center NY, a doctor sees every patient. You can choose a rapid test or a lab test.
Rapid tests, results in 30 minutes. Self-pay only. The price is the total; there is no office visit fee on top.
- Chlamydia and gonorrhea (urine or penile swab for men): $120.
- Chlamydia, gonorrhea and trichomoniasis (women): $180.
- Trichomoniasis (women): $70.
- HIV: $90.
- HIV and syphilis: $130.
- Syphilis: $80.
Lab tests. Throat and rectal swabs, hepatitis B and C, and herpes go to the lab, Northwell or Quest. Herpes is not part of the standard panel, so ask for it. Blood results take 1 to 2 days; urine and swab results take 3 to 5 days.
- If we take your insurance, it covers the visit and the lab tests. Your plan sets any copay or deductible.
- If we don't take your plan, or you have no insurance, the office visit is $90. The lab bills your insurance, or bills you directly if you have none.
See all our rapid STD testing options.
