What Tests Should You Take After Sex? The Complete Guide for London Patients

Marylebone Diagnostic Centre
Results within 24–42 hours. Westminster residents receive 20% off.

Many people search online for clear guidance about what to do after sex – especially after unprotected sex, a new partner, a missed pill, or a condom slip.
Search terms such as “What test should you take after sex?”, “How soon can you be tested?”, and “How soon after sex will a pregnancy test be positive?” are trending across London.

This article explains the exact tests you may need, the correct timing, and the options available at Marylebone Diagnostic Centre (MDC).

What Test Should You Take After Sex?

The answer depends on whether you are concerned about pregnancy, STIs or both.

For pregnancy concerns

You may need:
Urine pregnancy test
Blood pregnancy test (β-hCG)
These detect early pregnancy at different time intervals.

For STI concerns

You may need:
Chlamydia and Gonorrhoea test (urine + swab)
HIV 4th generation blood test
Syphilis blood test
Hepatitis B & C blood tests
Full STI Panel (urine + blood)

The correct timing matters, because testing too early can give false reassurance.

How Soon Can You Be Tested After Sex?

This is one of the most common questions London patients ask.

Pregnancy

Urine pregnancy test:

Most accurate 10–14 days after sex, depending on the test sensitivity.
Searches like “Pregnancy test 7 days after sex” are common, but results at 7 days can be false negative.

Blood pregnancy test (β-hCG):

Detectable 7–9 days after conception.
This is the earliest reliable pregnancy test available.

Chlamydia & Gonorrhoea

These can be tested from:
2–5 days after sex
This includes urine and vaginal/urethral swab testing.

HIV

4th generation (antigen + antibody) test is reliable from:
28 days after exposure
Earlier testing can still be done for guidance, but a follow-up is required.

Syphilis

Accurate from:
21–28 days after exposure

Hepatitis B & C

Accurate from:
4–6 weeks after exposure

MDC offers these blood and urine tests with rapid turnaround.

What If You Have Symptoms?

Many people also search for “Symptoms of STD in female” or “Symptoms of STD in male”.

Symptoms may include:

• Pain during urination
• Discharge
• Pelvic pain
• Lower abdominal discomfort
• Itching or irritation
• Bleeding after sex
• Testicular pain
• Rashes (syphilis)

If you have symptoms, you should test immediately, even if it is earlier than the recommended window period.
A repeat test may be required later.

Can You Get Tested Immediately After Sex?

Yes, but with limitations.

You can test immediately for:

• Chlamydia
• Gonorrhoea
• Pregnancy (blood β-hCG only after 7–9 days)
• UTIs
• Bacterial infections

You cannot reliably test immediately for:

• HIV
• Syphilis
• Hepatitis B/C

These require follow-up testing at the correct interval.

Pregnancy Testing After Sex

People often ask:

STI Testing Options in London

Search terms include:

• “Free STI test Manchester”
• “Free chlamydia test kit by post”
• “STI test near me London”

NHS Options

Free home STI kits are available through local NHS sexual health services for those eligible.
However, availability varies, and delays are common during busy periods.

Private options at MDC

• Walk-in availability
• Fast 24 – 42 hour results
• Discreet appointments
• Comprehensive STI panels
• Pregnancy blood tests
• No referral required
• Clear result explanations

Which STI Tests Should You Do After Unprotected Sex?

Recommended panel:

• Urine chlamydia and gonorrhoea
• HIV 4th gen
• Syphilis
• Hepatitis B & C
• Trichomonas (if symptomatic or high risk)
• Culture if symptoms of infection
• Urine analysis (if pain or burning)

MDC offers packages tailored to exposure type and timing.

When to Repeat Testing

Repeat testing is recommended at:

• 2–3 weeks
• 6 weeks
• 3 months (for HIV, syphilis and hepatitis, depending on exposure)

Your clinician will guide the correct schedule.

When to Seek Urgent Care

Seek urgent attention if you experience:

• Severe pelvic pain
• High fever
• Unusual bleeding
• Severe testicular pain
• Rashes with ulcers
• If you believe you were exposed to HIV in the last 72 hours (PEP may be needed)

MDC can guide you, but PEP is provided through NHS emergency sexual health or A&E.

Why Londoners Are Testing More Often

London has some of the highest STI rates in the UK.
Busy lifestyles, multiple dating apps, and inconsistent condom use increase the need for regular screening.
Professional workers, students and travellers account for the majority of testing at MDC.

Why Choose Marylebone Diagnostic Centre

• Discreet and private service
• Fast appointments
• Results within 24–42 hours
• Expert clinical interpretation
• Accurate blood and urine testing
• Five minutes from Baker Street
• Open Monday to Saturday

Westminster residents receive 20% off all profiles

Book Your Sexual Health Test

Marylebone Diagnostic Centre
73 Baker Street, London W1U 6RD
Tel: +44 7495 970109
Private, fast, discreet same-day testing in central London

Quick Links

• Pregnancy Blood Test (β-hCG)
• Chlamydia and Gonorrhoea Test
• Full STI Panel
• HIV 4th Generation Test
• Syphilis Test
• Hepatitis B & C Tests
• Urine Analysis Test
• Book an Appointment

Read More

• NHS – STI Testing and Services
• NHS – Pregnancy Testing
• NHS – HIV Testing
• Terrence Higgins Trust – HIV Window Period
• Brook – STI Symptoms and Testing