# How to use ovulation (LH) tests

> Pee sticks that give you a heads-up – here’s how to get the most out of them.

Category: Fertility & TTC · 4 min read · Written by the Splash team · Sources checked October 2026
URL: https://splash.care/learn/fertility-ttc/lh-tests-how-to

## Quick answer

- LH tests detect the surge that comes before ovulation.
- A positive usually means ovulation within about 36 hours.
- Test daily from around day 10 (later with longer cycles).
- Pair with BBT to confirm ovulation actually happened.

[Ovulation](https://splash.care/learn/glossary/ovulation) tests (often called OPKs) look for the [LH surge](https://splash.care/learn/glossary/lh-surge) – the [hormone](https://splash.care/learn/cycle-basics/hormones-explained) spike that tells your ovary “release the egg!”. A positive usually means [ovulation](https://splash.care/learn/phases/ovulation) is coming within about 36 hours, which makes them handy for planning.

**~36 hrs** Typical time from a positive LH test to ovulation (Cleveland Clinic)

## Step by step

1. Work out when to start. Cleveland Clinic suggests around day 10 of a typical cycle; with longer cycles, start a few days later.
2. Test at roughly the same time each day and read your test’s leaflet for its preferred time.
3. Try not to drink loads right before testing – very diluted pee can make the line fainter.
4. Read the result in the time window the leaflet gives. [A test](https://splash.care/tools/pregnancy-test-timing) line as dark as (or darker than) the control line usually counts as positive.
5. Keep testing daily until you get a positive, then [log it](https://splash.care/learn/cycle-basics/tracking-101) in the app.

> **Splash says:** a positive is your cue to have sex that day and the next day or two. Sperm love to be waiting when the egg arrives.

## When tests get confusing

- Faint lines on most days are normal – there’s always a little LH around.
- Some people with [PCOS](https://splash.care/learn/glossary/pcos) can have high LH levels much of the time, giving lots of positives.
- A positive shows the surge, not proof that an egg was released. A temperature rise afterwards helps confirm it.
- Some medications and recent [pregnancy](https://splash.care/learn/fertility-ttc/early-pregnancy-signs) can affect results – check the leaflet.

**Myth:** A positive LH test means you ovulated.

**Fact:** It means the surge happened and ovulation is likely soon. It can’t guarantee an egg was released.

### When to see a doctor

If you’ve tested for several cycles and never see a positive, your cycles are very irregular, or you keep getting positives all month, mention it to your GP – they may want to check how you’re ovulating.

**Quick quiz:** You get a positive LH test on Tuesday morning. When is ovulation most likely?

1. The previous weekend
2. Within about the next day and a half
3. In a week

Answer: Within about the next day and a half. Ovulation typically follows within about 36 hours of a positive test.

## Sources

1. [Cleveland Clinic – Ovulation](https://my.clevelandclinic.org/health/articles/23439-ovulation)
2. [NHS – Trying to get pregnant](https://www.nhs.uk/pregnancy/trying-for-a-baby/planning-your-pregnancy/)
3. [Cleveland Clinic – Anovulation](https://my.clevelandclinic.org/health/diseases/21698-anovulation)

This is general information, not medical advice. Splash can’t diagnose. If you’re worried, talk to a GP, pharmacist or sexual health clinic. In an emergency call 999 (UK) or 911 (US).