Ovulation is the release of a mature egg from an ovary, typically occurring around day 14 of a 28-day menstrual cycle. The fertile window spans approximately 6 days surrounding ovulation.
How Ovulation Works
Each month, rising estrogen triggers a surge of luteinizing hormone (LH), which causes the dominant follicle in the ovary to release an egg. The egg travels down the fallopian tube where it can be fertilized for 12-24 hours. Sperm can survive up to 5 days, creating a fertile window of about 6 days.
Signs of Ovulation
- Change in cervical mucus (becomes clear, stretchy, egg-white consistency)
- Slight rise in basal body temperature (0.4-1.0°F after ovulation)
- Mild pelvic pain or cramping (mittelschmerz)
- Positive ovulation predictor kit (OPK) detecting LH surge
Real-World Example
With a 30-day cycle: ovulation likely occurs around day 16 (30 − 14 = 16). The fertile window runs from approximately day 11 through day 16. To conceive, timing intercourse during this window maximizes chances.
Frequently Asked Questions
Can you ovulate more than once per cycle?
In rare cases, two eggs may be released within 24 hours of each other (which can result in fraternal twins). However, once the progesterone rise confirms ovulation, a second ovulation later in the same cycle does not occur.
Can you get pregnant outside the fertile window?
Conception is extremely unlikely outside the fertile window. However, cycle length variations mean the fertile window is not always predictable. Sperm survival of up to 5 days means intercourse before ovulation can still result in pregnancy.
Does ovulation happen on the same day each month?
Not necessarily. Ovulation timing varies based on cycle length, stress, illness, and hormonal fluctuations. Even women with regular cycles can ovulate 1-2 days earlier or later than expected.