When Do STI Symptoms Start and When Do Tests Turn Positive?

Why Timing Matters

If you've had a potential STI exposure, you're probably anxious to know two things: when might symptoms appear, and when can you get tested?

Understanding these timelines is crucial because:

• Testing too early may give false negative results
• Symptoms don't always appear, even with infection
• Knowing the "window period" helps you plan appropriate testing

Let's break down the timing for each major STI.

Two Important Concepts

Incubation Period

The time between exposure and when symptoms might first appear. Remember: many STIs never cause symptoms.

Window Period

The time between exposure and when a test can accurately detect the infection. Testing during the window period may give a false negative.

These aren't the same thing – you might develop symptoms before or after a test would show positive, or never develop symptoms at all.

Complete STI Timeline Guide

Chlamydia

Incubation period: 7-21 days (but often no symptoms)

When symptoms appear (if they do):

• Usually 1-3 weeks after exposure
• 70% of women and 50% of men never have symptoms
• Symptoms can be mild and overlooked

Window period for testing: 2 weeks

• NAAT tests (standard urine/swab tests) detect infection from about 14 days post-exposure
• Testing earlier may miss recent infections

When to test: From 2 weeks after exposure; retest if negative but concerned

Gonorrhoea

Incubation period: 1-14 days (typically 2-5 days)

When symptoms appear (if they do):

• Often within 2-5 days for men with urethral infection
• Women and throat/rectal infections often asymptomatic
• Up to 50% of women and 10% of men have no symptoms

Window period for testing: 2 weeks

• NAAT tests accurate from about 14 days post-exposure
• Some laboratories suggest testing from 7 days

When to test: From 2 weeks after exposure for reliable results

Syphilis

Incubation period: 10-90 days (typically 21 days)

When symptoms appear:

• Primary stage (chancre/sore): Usually 2-4 weeks after exposure, range 10-90 days
• Secondary stage (rash, flu-like): 4-10 weeks after chancre appears
• Chancres are often painless and may go unnoticed, especially if internal

Window period for testing: 4-6 weeks (for standard tests)

• Blood tests look for antibodies, which take time to develop
• Testing at 4 weeks will detect most infections
• Full confidence at 12 weeks (3 months)

When to test: 4-6 weeks after exposure; repeat at 12 weeks if initially negative

HIV

Incubation period: 2-6 weeks for acute retroviral syndrome (if it occurs)

When symptoms appear:

• Acute HIV (if symptomatic): Usually 2-4 weeks after exposure
• Symptoms resemble flu: fever, fatigue, rash, swollen glands
• Up to 40% have no acute symptoms
• Without treatment, AIDS develops in 8-10 years on average

Window period for testing: Depends on test type

• 4th generation (antigen/antibody) tests: 4-6 weeks (detects most infections from 28 days)
• Rapid antibody tests: 12 weeks for complete accuracy
• PCR/viral load tests: 10-14 days (not routinely used for screening)

When to test:

• 4 weeks for 4th generation test (95% accuracy)
• Repeat at 12 weeks for definitive result

Herpes (HSV-1 and HSV-2)

Incubation period: 2-12 days (typically 4 days)

When symptoms appear:

• First outbreak (if symptomatic): Usually 2-12 days after exposure
• First outbreak is often the most severe
• Many people have mild or unrecognised initial outbreaks
• Up to 80% of people with herpes don't know they have it

Window period for testing: 12 weeks for blood tests

• Swab tests can diagnose active sores immediately
• Blood tests detect antibodies, which take 12 weeks to develop reliably
• Blood tests can give false negatives before 12 weeks

When to test:

• If sores present: swab immediately
• Blood test: from 12 weeks post-exposure
• Blood testing isn't routinely recommended without symptoms

HPV (Human Papillomavirus)

Incubation period: Weeks to months (highly variable)

When symptoms appear:

• Genital warts: Usually 2-3 months after exposure, but can be weeks to years
• Cell changes: May take years to develop; detected through cervical screening
• Most HPV infections cause no symptoms and clear naturally

Window period for testing: N/A for routine testing

• There's no routine HPV test for men or for women outside cervical screening
• Cervical screening (smear tests) detect high-risk HPV in women from age 25
• Visible warts can be diagnosed clinically

When to test: Attend regular cervical screening; see a clinician if you notice warts

Hepatitis B

Incubation period: 6 weeks to 6 months (average 90 days)

When symptoms appear:

• If symptomatic: Usually 2-3 months after exposure
• Many adults have no symptoms during acute infection
• Symptoms may include jaundice, fatigue, nausea, abdominal pain

Window period for testing: 6 weeks to 3 months

• Tests detect hepatitis B surface antigen (HBsAg)
• May be detectable from 4 weeks but can take up to 12 weeks
• Antibody tests take longer to become positive

When to test: 6 weeks after exposure; repeat at 3 months if initially negative

Trichomoniasis

Incubation period: 5-28 days

When symptoms appear:

• Usually within 5-28 days
• Up to 70% of people have no symptoms
• Women more likely to be symptomatic than men

Window period for testing: 2 weeks

• NAAT tests accurate from about 14 days
• Can be tested alongside other STIs

When to test: From 2 weeks after exposure

Mycoplasma genitalium

Incubation period: 1-3 weeks

When symptoms appear:

• Usually 1-3 weeks after exposure
• Many cases are asymptomatic
• Symptoms similar to chlamydia

Window period for testing: 2-3 weeks

• Requires specific NAAT testing (not always included in standard screens)
• May need to request specifically

When to test: From 2-3 weeks after exposure

Quick Reference Table

What If You Can't Wait?

If you've had a high-risk exposure and are anxious:

Consider Testing Anyway

• Early testing can detect established infections (from previous exposures)
• A negative result now can be reassuring, with follow-up testing later
• Some infections become detectable earlier than the standard window

Treat Symptoms

• If you develop symptoms, seek care immediately regardless of timing
• Symptomatic infections can often be diagnosed and treated promptly

The Bottom Line

Timing matters for accurate STI testing, but don't let window periods prevent you from seeking help. If you're concerned, get tested – even if you need follow-up testing later for complete reassurance.

Book Your Test

We offer comprehensive STI screening with expert guidance on timing. Whether you need immediate testing or advice on when to test, we're here to help. Book your confidential appointment today.