Ovulation Calculator
Normal range: 21-40 days (average is 28)
Quick Facts
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Understanding Ovulation
What is Ovulation?
Ovulation is the release of a mature egg from an ovary. It typically occurs once per menstrual cycle, about 14 days before your next period starts. The egg travels down the fallopian tube where it can be fertilized by sperm.
The Menstrual Cycle
Menstrual Phase (Days 1-5)
The uterine lining sheds. Day 1 is the first day of your period. Low fertility during this phase.
Follicular Phase (Days 1-13)
Follicles develop in the ovaries. Estrogen rises. Fertility increases as ovulation approaches.
Ovulation (Day 14)
Mature egg is released from the ovary. Peak fertility - best time for conception.
Luteal Phase (Days 15-28)
Progesterone rises. If no pregnancy, hormone levels drop and the cycle begins again.
The Fertile Window
The fertile window is the time during your cycle when pregnancy is possible. It spans about 6 days - the 5 days before ovulation and the day of ovulation itself.
Why 5 Days Before?
Sperm can survive in the female reproductive tract for up to 5 days. This means having intercourse before ovulation can still result in pregnancy if sperm are present when the egg is released.
Signs of Ovulation
Cervical Mucus Changes
Around ovulation, cervical mucus becomes clear, stretchy, and similar to egg whites - this is the most fertile type.
Basal Body Temperature
Temperature rises slightly (0.2-0.5°F) after ovulation and stays elevated until your next period.
Ovulation Pain (Mittelschmerz)
Some women feel a twinge or cramp on one side of the lower abdomen when the egg is released.
LH Surge
Luteinizing hormone spikes 24-36 hours before ovulation. Ovulation predictor kits detect this surge.
Factors Affecting Ovulation
- Age: Fertility peaks in early 20s and declines after 35
- Stress: Can delay or prevent ovulation
- Weight: Being significantly under or overweight can affect cycles
- Exercise: Excessive exercise may disrupt ovulation
- Medical conditions: PCOS, thyroid disorders can affect cycles
- Medications: Some medications can impact ovulation
Important Note
This calculator provides estimates based on average cycle patterns. Actual ovulation can vary from cycle to cycle, even in women with regular periods. For the most accurate tracking, consider combining calendar methods with ovulation predictor kits, basal body temperature tracking, or cervical mucus monitoring.
Frequently Asked Questions
When is the best time to get pregnant?
The best time to conceive is during your fertile window - the 5 days before ovulation and the day of ovulation itself. The highest pregnancy rates occur when intercourse happens 1-2 days before ovulation. Sperm can survive up to 5 days in the reproductive tract, while the egg is only viable for 12-24 hours after release.
How do I know when I'm ovulating?
Signs of ovulation include changes in cervical mucus (becomes clear and stretchy like egg whites), slight rise in basal body temperature (0.2-0.5 degrees F after ovulation), mild pelvic pain on one side (mittelschmerz), and a positive ovulation predictor kit that detects the LH surge 24-36 hours before ovulation.
Can I get pregnant outside my fertile window?
Pregnancy is highly unlikely outside the fertile window. The egg only survives 12-24 hours after ovulation, and sperm typically survive 3-5 days (maximum). If intercourse occurs more than 5 days before ovulation or more than 1 day after, the chances of conception are very low.
Why might my ovulation day vary from the calculator's prediction?
Ovulation calculators assume a standard 28-day cycle with ovulation on day 14, but actual ovulation timing varies based on stress, illness, travel, weight changes, and natural cycle variation. Even women with regular cycles can ovulate a few days earlier or later than predicted. For more accuracy, combine calendar methods with physical signs of ovulation.