How to Track Ovulation: Every Method Compared
Method 1: LH Ovulation Test Kits (OPKs)
Detect the LH surge 24–36 hours before ovulation. Accuracy: 97–99%. Best for most couples — first-line.
Strip tests: Cheapest. Compare test to control line. ₹150–₹400 for 10 strips. Requires practice to read. Digital tests: Clear "peak" smiley face. ₹800–₹1,500. More user-friendly. Dual-hormone monitors: Track estrogen + LH. Show 4+ fertile days. ₹2,000–₹4,000. Most information.
When to start: Day 10 for 28-day cycle; day 8–10 for irregular cycles. Test at same time daily (afternoon/early evening is slightly more sensitive).
On a positive test: Have intercourse that day and the following day — your two most fertile days.
PCOS limitation: Chronically elevated LH in PCOS can cause persistent positives or no clear surge. BBT charting alongside OPKs is helpful for confirmation.
Method 2: Basal Body Temperature (BBT)
Temperature rises 0.2–0.5°C after ovulation (progesterone effect). Confirms ovulation retrospectively — cannot predict it in advance.
How: Digital basal thermometer before getting out of bed, same time each morning, after 4+ hours sleep. Chart on Fertility Friend app or paper chart.
Disrupted by: Poor sleep, illness, alcohol, shift work, different wake times.
Best for: Confirming ovulation occurred; understanding cycle patterns; PCOS patients where OPKs are unreliable (confirms whether LH surge was followed by actual ovulation).
Method 3: Fertility Apps
Calendar algorithms predict ovulation from past cycle lengths. Poor for predicting ovulation in irregular cycles. Best used as a data tracker alongside OPK results, not as a standalone predictor.
A study of 12 popular period/fertility apps found inaccurate fertile window predictions for women with irregular cycles. Works reasonably for women with very regular cycles of consistent length.
Method 4: Ultrasound Follicle Tracking
Gold standard. Directly measures follicle growth (target: 17–20mm before ovulation). Confirms endometrial thickness and post-ovulation follicle rupture.
Cost: ₹1,500–₹3,500 per scan. Typically 2–3 scans per cycle.
Best for: After 6 months of OPK-guided timing without success; women on ovulation induction (mandatory monitoring); irregular cycles where OPKs are unreliable.
Summary
| Method | Predicts Ovulation? | Confirms Ovulation? | Cost | Best For |
|---|---|---|---|---|
| OPK strips | Yes (24–36h before) | No | Low | Most TTC couples |
| BBT | No | Yes (next day) | Very low | Pattern confirmation |
| Fertility app | Approximately | No | Free-Low | Data tracking only |
| Ultrasound | Yes (most accurate) | Yes | High | After 6 months; stimulation |
Reference: ASRM 2021 — Fertility Evaluation. NICE CG156 — Fertility, updated 2023.
Frequently Asked Questions
Which ovulation test is most accurate?▾
Transvaginal ultrasound follicle tracking is the gold standard — it directly observes follicle growth and confirms ovulation. For home use, LH ovulation test kits (OPKs) are 97–99% accurate at detecting the LH surge when used correctly. Digital OPKs are more reliable than strip tests for first-time users. Fertility apps with only calendar algorithms are the least accurate, particularly for irregular cycles.
Can you miss the LH surge with an ovulation test?▾
Yes — if testing once daily at inconsistent times, or if your surge is short (under 24 hours). Test at the same time each afternoon or early evening. If you consistently get negatives but have a short cycle, test twice daily (morning and evening) during your predicted ovulation window.
Do fertility apps accurately predict ovulation?▾
Calendar-only fertility apps are unreliable for predicting exact ovulation date — they predict based on average cycle length, not your actual current cycle. They work reasonably for women with very consistent, regular cycles. For irregular cycles, PCOS, post-pill cycles, or perimenopause, use OPK tests rather than relying on app predictions.