Ovulation tests detect the surge in luteinizing hormone (LH) in urine that usually comes 24 to 36 hours before ovulation. Simple strips compare a test line with a control line; digital tests read the result for you; fertility monitors track more than one hormone across your cycle. Start testing a few days before your expected surge, follow the instructions, and talk to a doctor if results are confusing or cycles are irregular.
Ovulation tests help you spot your most fertile days by measuring hormones in urine.
How they work
Luteinizing hormone (LH) rises sharply before ovulation. Tests detect that surge, and ovulation usually follows within about 24 to 36 hours.
Types of test
| Type | What it shows | Notes |
|---|---|---|
| LH strips | Test line vs control line | Lowest cost; you read the lines |
| Digital LH tests | Clear yes or no symbol | Easier to read |
| Dual-hormone digital tests | LH plus estrogen | Shows a wider fertile window |
| Fertility monitors | Hormone tracking across the cycle | Higher cost, more data |
Testing tips
- Follow the brand’s start-day chart for your cycle length.
- Test at the same time each day, as instructed.
- Avoid drinking lots of fluid just before testing.
- Record results in a cycle tracking app if you use one.
When to talk to a doctor
If your cycles are very irregular, you never see a surge, or you have been trying to conceive for a while without success, a doctor can help.
Browse fertility and ovulation or learn about menstrual cups and discs.
Common questions
When should I start testing?
Many brands suggest starting a few days before the expected surge based on your usual cycle length. Each test's instructions include a start-day chart.
What can affect results?
Irregular cycles, some medications and conditions such as PCOS can make LH tests harder to interpret. Talk to your doctor if results do not make sense.
Are digital tests more accurate than strips?
Both detect LH. Digital tests remove the need to judge line darkness and some also detect estrogen to show more fertile days.
Can I use an ovulation test as contraception?
Standard ovulation tests are not designed or cleared as contraception. Speak to a healthcare professional about contraception options.