Ovulation: When You’re Most Fertile and How to Track It

You're only fertile for a short window each cycle — roughly six days. That’s the six days when sex can lead to pregnancy: the five days before ovulation and the day of ovulation itself. Knowing those days makes a big difference if you’re trying to conceive or trying to avoid pregnancy.

Ovulation happens when an ovary releases a mature egg. For many people with regular cycles that run about 28 days, ovulation falls around day 14 — but cycles vary, and ovulation is best measured backward from when your next period starts, not forward from the last one. Some cycles don’t include ovulation at all, especially when stress, weight changes, or health issues are involved.

What does ovulation feel like? You may notice thinner, stretchy cervical mucus that looks like egg white. Some people feel a one-sided twinge or mild cramp called mittelschmerz. Basal body temperature (BBT) rises slightly after ovulation. Libido can increase, and breasts may feel tender. Any single sign can be misleading, so combine methods for better accuracy.

How to track ovulation

There are simple ways to pin it down. Use a calendar only if your cycles are steady. Ovulation predictor kits (OPKs) detect the LH surge that usually precedes ovulation by 24–36 hours — a positive test tells you to have sex in the next day or two. For timing, many people test once a day, or twice a day if cycles are short or unpredictable.

BBT tracking needs a special digital thermometer and daily readings first thing in the morning before moving. After ovulation your temperature usually rises 0.3–0.5°C (about 0.5–1°F). Charting three months gives a clearer pattern. Check cervical mucus daily: egg-white, slippery mucus points to imminent ovulation. Fertility apps and wearable trackers can help spot patterns, but they estimate — use them with OPKs or BBT for real confidence.

When to talk to a clinician

If you’re under 35 and haven’t conceived after 12 months of regular, unprotected sex, or if you’re over 35 and haven’t conceived after 6 months, see a clinician. Also see help sooner if your cycles are very irregular, you bleed between periods, you have severe pelvic pain, or you have known medical conditions like PCOS or thyroid issues. A clinician can order hormone tests, ultrasound, and talk about treatments or referrals.

Many people boost accuracy by combining methods: use OPKs plus BBT and mucus charts. Avoid drinking alcohol or sleeping in later than usual before BBT checks. Skip oil-based lubricants near fertile days — they can harm sperm. Small routine changes often sharpen your results. Start today.

Quick practical tips: track for at least three cycles to see a pattern; use the same thermometer and take BBT at the same time; test LH in the afternoon for many people; have sex every 24–48 hours during the fertile window. If you want personalized advice, bring your cycle notes to your appointment — it speeds things up.

Understanding ovulation puts control back in your hands. Track smart, ask questions, and get help if patterns don’t match your goals.