Ovulation Calculator
Predict your most fertile days and ovulation date based on your menstrual cycle. Plan conception or track your fertility window.
Normal range: 21–35 days. Average is 28 days.
Days from ovulation to next period. Default 14 is typical; leave unchanged if unsure.
Enter your LMP date to see results
Complete Guide to Ovulation & Fertility
How Ovulation Works
Ovulation is the release of a mature egg from the ovary, which then travels down the fallopian tube where fertilization can occur. It typically happens once per cycle, approximately 14 days before your next period (the luteal phase). The egg remains viable for fertilization for only 12–24 hours after release, which is why timing is crucial for conception.
Understanding the Fertile Window
Despite the egg lasting only 12–24 hours, the fertile window spans about 6 days. This is because sperm can survive in the female reproductive tract for up to 5 days. The most fertile days are the 2 days before and the day of ovulation. Studies show the highest conception rates occur when intercourse happens 1–2 days before ovulation, as sperm are already present when the egg is released.
Signs of Ovulation
Cervical Mucus Changes
Mucus becomes clear, stretchy, and "egg-white" consistency near ovulation. This is the most reliable physical sign.
Basal Body Temperature
BBT rises 0.2–0.5°C after ovulation due to progesterone. Track daily to confirm ovulation occurred (but it's a retrospective indicator).
LH Surge (OPK Test)
Luteinizing hormone surges 24–36 hours before ovulation. Ovulation predictor kits detect this surge in urine.
Mild Pelvic Pain
Some women experience "mittelschmerz" — a brief, mild pain on one side of the lower abdomen during ovulation.
Factors That Affect Ovulation
Cycle length can vary due to stress, illness, travel, extreme exercise, significant weight changes, hormonal conditions (PCOS, thyroid disorders), and age. Women in their late 30s and 40s may notice shorter, more irregular cycles. If your cycle is consistently shorter than 21 days or longer than 35 days, consult a healthcare provider.
Frequently Asked Questions
Can I get pregnant on my period?
It's unlikely but possible, especially with shorter cycles (21–24 days). If you ovulate early and sperm from period-end intercourse survives 5 days, fertilization can occur.
Is ovulation always on Day 14?
No. Day 14 is average for a 28-day cycle. Ovulation timing depends on when the LH surge occurs, which can vary. In a 32-day cycle, ovulation may occur around Day 18.
How long should I try before seeing a doctor?
General guidelines: under 35 — try for 12 months; age 35–39 — try for 6 months; over 40 — consult immediately. These timelines assume regular, well-timed intercourse.