Understanding Ovulation and Your Cycle
Your menstrual cycle begins on the first day of your period. Ovulation — the release of an egg from an ovary — occurs approximately 14 days before your NEXT period, not 14 days from the start of your current cycle. This is why the timing varies based on your cycle length.
The Fertile Window Explained
Sperm can survive in the female reproductive tract for up to 5 days under ideal conditions. The egg survives 12–24 hours after ovulation. Combined, this creates a fertile window of approximately 6 days — the 5 days before ovulation and ovulation day itself. Having intercourse in the 1–2 days before ovulation gives the highest probability of conception.
Physical Signs of Ovulation
Many women notice physical signs around ovulation: cervical mucus becomes clear, stretchy and slippery (like raw egg white) — this is the most reliable physical sign. Basal body temperature rises by 0.2–0.5°C after ovulation and stays elevated until the next period. Some women experience mild one-sided pelvic pain (mittelschmerz). Ovulation predictor kits (OPKs) detect the LH hormone surge 24–36 hours before ovulation and are the most accurate at-home method.
Frequently Asked Questions
When do I ovulate?
Ovulation occurs about 14 days before your next period — not 14 days after your last one. For a 28-day cycle that's day 14; for a 32-day cycle it's day 18; for a 24-day cycle it's day 10. Your fertile window includes the 5 days before ovulation plus ovulation day itself.
What is my fertile window?
The fertile window is the 6 days when pregnancy is possible: the 5 days before ovulation (sperm can survive up to 5 days) and ovulation day itself (the egg survives 12–24 hours). The 1–2 days right before ovulation are the most fertile.
How accurate is calendar-based ovulation prediction?
Most accurate for women with very regular cycles. Less reliable if your cycle varies by more than 2–3 days each month. For greater accuracy, use ovulation predictor kits (OPKs) that detect the LH surge occurring 24–36 hours before ovulation.
What is the luteal phase?
The luteal phase is the second half of your cycle from ovulation to your next period. It typically lasts 12–16 days and is relatively consistent for each woman. A luteal phase under 10 days can make implantation difficult and may indicate a hormonal imbalance worth discussing with a doctor.
Can I get pregnant outside my fertile window?
Very unlikely but not impossible. Ovulation timing can shift unexpectedly due to stress, illness or hormonal changes. For this reason, calendar-based methods alone are not reliable contraception.