Ovulation: when it happens and how to catch your fertile window

You have only a short window each cycle when pregnancy is possible — usually about six days. Knowing when you ovulate makes those days count. This quick guide tells you what ovulation looks like, how to track it, and what to do if your cycle feels unpredictable.

What is ovulation and when does it happen?

Ovulation is when an ovary releases an egg. In a regular 28-day cycle it often happens around day 14, but most people don’t have perfect 28-day cycles. If your cycle is shorter or longer, ovulation shifts. The fertile window is roughly five days before ovulation plus the day of ovulation, because sperm can live in the body for several days.

Simple signs you can watch for

Cervical mucus: Look for clear, stretchy mucus that feels like raw egg white — that’s a strong sign you’re near ovulation. Check daily after your period to notice changes.

Basal body temperature (BBT): Your resting morning temperature rises slightly after ovulation. Track BBT daily with a basal thermometer; a sustained rise usually confirms ovulation happened, but it doesn’t predict it.

LH surge tests (ovulation predictor kits): These urine tests detect the luteinizing hormone spike that triggers ovulation. Start testing a few days before you expect to ovulate based on your cycle length.

Ovulation pain and breast tenderness: Some people feel a brief twinge (mittelschmerz) or notice mild breast soreness. These signs can help, but they aren’t reliable alone.

How to time sex: Aim for intercourse every 1–2 days during the fertile window. If you prefer fewer sessions, have sex on alternate days starting five days before your expected ovulation. That gives sperm the best chance when the egg is released.

If your cycles are regular, use the calendar to estimate when to start OPKs. For irregular cycles, pair OPKs with mucus checks and consider tracking for several months to learn patterns.

When to see a doctor: If you’re under 35 and haven’t conceived after a year of trying, or over 35 and haven’t conceived after six months, get medical help. Also see a provider if your periods are very irregular, very painful, or stop altogether. A simple blood test (progesterone in the luteal phase) can confirm whether ovulation is occurring.

Common causes of missed ovulation include stress, big weight changes, intense exercise, and conditions like polycystic ovary syndrome (PCOS). Treatments range from lifestyle changes to medications that help trigger ovulation — those require a doctor’s plan and monitoring.

Quick checklist: track cycles for three months, watch cervical mucus daily, use OPKs around expected ovulation, check BBT for confirmation, and contact a clinician if cycles are irregular or pregnancy isn’t happening. Small habits—timing, simple tracking, and timely help—make a big difference.