Ovulation · 6 minute read
LH tests and ovulation predictor kits
What a positive urine test means, when ovulation may follow, and why an LH surge is not a guarantee.
Evidence-informed · Editorial review August 2026 · Links to trusted sources are available in the interactive app
What the test detects
Ovulation predictor kits detect luteinizing hormone in urine. LH usually rises before ovulation, so a positive result can identify a period of higher fertility.
Positive does not mean confirmed
A test detects a hormone surge, not egg release itself. Some cycles may have more than one surge, and conditions such as PCOS can complicate interpretation. Follow the product instructions because timing and thresholds vary.
Combine signals thoughtfully
A sequence of LH results, cervical mucus, and later temperature data can provide more context than any single signal. Seek clinical guidance if results are repeatedly confusing or pregnancy is not occurring when expected.