Condoms are a highly effective method for preventing the transmission of HIV during sex. Still, many people don’t use condoms or use them consistently. Also, in some cases, condoms may break during sex.

If a person thinks they may have been exposed to HIV through condomless sex, or due to a broken condom, they’ll want to make an appointment with a healthcare professional as soon as possible.

If a person sees a healthcare professional within 72 hours, they may be eligible to start a medication to reduce their chance of contracting HIV. They can also set up an appointment to be tested for HIV and other sexually transmitted infections (STIs).

Read on to learn more about:

  • how soon to be tested for HIV after condomless sex
  • the main types of HIV tests
  • preventive medications
  • the risk factors of different forms of condomless sex

If a person believes they’ve been exposed to HIV, it’s important for them to see a healthcare professional as soon as possible.

No test can accurately detect HIV in the body immediately after exposure. There’s a time frame or window period before a person can be tested for HIV and receive accurate results.

Regardless of the type of test after potential HIV exposure, a person should get tested again after the window period has passed to be certain.

People with a higher chance of contracting HIV should get regularly tested every 3 months to 1 year.

How soon can a blood test detect HIV?

The window period is when a person is first exposed to HIV and when the virus will show up on types of HIV blood tests.

The window period can last 10 to 90 days, depending on their body’s immune response and the type of test that they’re taking.

A person may receive a negative test result during the window period even though they’ve contracted HIV.

A person can still transmit HIV to others during this window period. Transmission may even be more likely because there are higher virus levels in a person’s body during the window period.

Here’s a quick breakdown of the types of HIV tests and the window periods for each.

Rapid antibody tests

This test measures antibodies to HIV. The body can take up to 3 months to produce these antibodies.

It’s called a rapid test because results are typically ready less than 30 minutes after a person takes the test.

According to HIV.gov, a person can take a rapid antibody test 23 to 90 days after possible HIV exposure.

If someone takes this test 4 weeks after exposure, a negative result may be accurate. Still, it’s best to test again after 3 months to be sure. At 12 weeks or about 3 months, 97 percent of people have enough antibodies for an accurate HIV test result.

Rapid antibody/antigen tests

Rapid antibody/antigen tests are sometimes referred to as fourth-generation tests. A healthcare professional can order this type of test, which must be conducted at a lab.

This type of test measures both antibodies and levels of the p24 antigen, which can be detected as soon as 18 days after possible exposure.

Most people will produce enough antigens and antibodies for these tests to detect HIV at 18 to 45 days after exposure or 18 to 90 days with a finger prick test.

If a person tests negative a few weeks after they think they may have been exposed to HIV, a healthcare professional will likely recommend another test in 1 to 2 weeks. This test can produce false negatives in the very early stages of contracting HIV.

Nucleic acid tests (NATs)

A nucleic acid test (NAT) can measure the amount of virus in a blood sample. Some NATs provide positive or negative results, while others provide a viral load count.

These tests are more expensive than other forms of HIV testing. A healthcare professional will order only one if they think there’s a good chance a person was exposed to HIV or if screening test results were indeterminate.

There’s typically enough viral material present for a positive result 10 to 33 days after possible exposure to HIV.

Home testing kits

Most home testing kits contain antibody tests. They use one of the following to detect HIV:

  • oral swab sample
  • blood sample from a finger prick
  • urine sample

Depending on the test, people will either collect their sample and send it off to a lab or take the test kit to a lab and have the test performed there.

Generally speaking, test results are most likely to be accurate if a person waits 90 days to see if antibodies develop.

The HIV RNA Early Detection Test from STDCheck.com is a home test that uses a person’s genetic material to determine whether they have HIV. According to the manufacturers, the test can detect HIV 9 to 11 days after exposure.

The best HIV home tests

Check out our picks for the best rapid HIV tests that you can take at home.

How quickly a person can see a healthcare professional after exposure to HIV can significantly affect their chances of contracting the virus.

If a person believes they’ve been exposed to HIV or have an increased chance of being exposed to HIV, they should visit a healthcare professional within 72 hours. The healthcare professional may offer the antiretroviral treatment postexposure prophylaxis (PEP).

PEP can reduce a person’s chances of contracting HIV. PEP is typically taken once or twice daily for 28 days.

PEP has little or no effect if taken more than 72 hours after exposure to HIV, according to the Centers for Disease Control and Prevention (CDC). The medication isn’t usually offered unless it can be started within the 72-hour window.

During condomless sex, HIV in one person’s bodily fluids may be transmitted to another person’s body through the mucous membranes of the penis, vagina, or anus.

Of all types of condomless sex, HIV can be transmitted most easily during anal sex. This is because the lining of the anus is delicate and prone to damage, which can provide entry points for HIV.

Receptive anal sex, often called bottoming, is more likely to result in HIV exposure than insertive anal sex, or topping.

HIV can also be transmitted during vaginal sex without a condom, although the vaginal lining isn’t as susceptible to rips and tears as the anus.

The chance of acquiring HIV from having oral sex without using a condom or dental dam is very low. It would be possible for HIV to be transmitted if the person giving oral sex has mouth sores or bleeding gums or if the person receiving oral sex has recently contracted HIV.

Anal, vaginal, or oral sex without a condom or dental dam can lead to transmission of other STIs, too.

The most effective way to prevent HIV transmission during sex is to use a condom. Get a condom ready before any sexual contact occurs because HIV can be transmitted through pre-ejaculate, vaginal fluid, and from the anus.

Lubricants can also aid in reducing HIV transmission by helping prevent anal or vaginal tears. The right lubricants also help prevent condoms from breaking.

Only water-based lubricants should be used with condoms. Oil-based lubricants can weaken latex and sometimes cause condoms to break.

The use of a dental dam also effectively reduces a person’s chances of HIV transmission.

Preexposure prophylaxis (PrEP)

Preexposure prophylaxis (PrEP) is a once-daily antiretroviral treatment regimen. It helps prevent HIV transmission.

People with known risk factors for HIV should begin a PrEP regimen, according to a recommendation from the US Preventive Services Task Force (USPSTF).

Women who have sex with women are generally at low risk of contracting HIV through sex. Per the USPSTF recommendation, other people have an increased chance of contracting HIV if one of the following statements is applicable:

  • They’re in a sexual relationship with someone who’s living with HIV.
  • They’ve had syphilis or gonorrhea within the past 6 months.
  • They’re a man who has sex with men, and they’ve had chlamydia within the past 6 months.
  • They’re a man who has sex with men, and they use condoms inconsistently during anal sex.
  • They use condoms inconsistently during heterosexual sex, and their partner has an unknown HIV status and known risk factors for HIV.

People of all sexual orientations are at an increased risk of contracting HIV if they use injected drugs and share the equipment with others.

PrEP provides a high level of protection against HIV, practically eliminating a person’s risk when the medication is taken as prescribed. However, it’s still best to use condoms, too. PrEP protects against HIV only, not other STIs.

Can a person test too early for HIV?

Yes, it’s possible to test too early for HIV. If a person takes an HIV test too soon after possible exposure to HIV — and before the window period ends — they may not receive accurate test results.

How accurate is an HIV test after 2 weeks?

It will depend on the type of HIV test. Generally speaking, HIV tests are highly accurate when they’re performed correctly and after the proper window period.

An antibody test may not be accurate after 2 weeks because it typically takes the body a few weeks or even months to produce HIV antibodies.

An antibody/antigen test can technically detect HIV in as little as 18 days, or about 2.6 weeks.

According to a 2017 study, only 25 percent of people with HIV will receive a positive test result within 13.0 to 14.8 days of taking an antibody/antigen test. After 17.8 to 19.2 days, that ratio improves to 50 percent. After 43.1 to 44.3 days, the test will detect HIV in 99 percent of HIV-positive people.

An RNA test can detect HIV in 10 to 14 days, according to the San Francisco AIDS Foundation. The National Cancer Institute states that an RNA test can detect HIV 9 to 11 days after transmission.

Can a person test positive for HIV after 1 week?

Yes. According to StatPearls, some HIV RNA tests are sensitive enough to detect the virus as soon as 5 to 10 days after exposure to HIV.

Will HIV show up in a standard blood test?

Standard blood tests, such as the complete blood count, are unable to detect HIV. But if a person has a low red blood cell count or a high white blood cell count, a healthcare professional may suspect they have an infection.

If a person is possibly exposed to HIV through sex without a condom, they should make an appointment as soon as possible to speak with a healthcare professional. PEP medication may be recommended to reduce the chances of HIV transmission. A healthcare professional can also discuss a good timeline for HIV testing and testing for other STIs.