How Do You Calculate Your Most Fertile Days?

Many women use ovulation calendars or period tracking apps to help predict when they will ovulate and be most fertile. Other methods, including observing cervical fluid, taking daily basal body temperature, and tracking periods can also help a woman identify when she is ovulating and what her most fertile days will be.

Ovulation occurs in the menstrual cycle every month when a mature egg is released from an ovary and travels through the fallopian tube, where fertilization by sperm can occur. 

The lining of the uterus is thickened to prepare for a fertilized egg. If conception does not occur, the uterine lining is shed during the menstrual period.

Certain signs and symptoms can occur when a woman is ovulating, including:

• Breast tenderness
• Pain or dull ache felt on one side of the abdomen when ovulation occurs
• Change in cervical fluid
• Change in cervical position and firmness
• Basal body temperature increase that is sustained
• Light spotting
• Abdominal bloating
• Heightened sense of vision, smell, or taste
• Increased sex drive
• Elevated levels of luteinizing hormone, which can be detected on an ovulation test

A woman is most fertile in the window in which she is ovulating, and women who are trying to become pregnant may use ovulation prediction to determine their most fertile days and optimal time to have intercourse.

Many women use ovulation calendars or period tracking apps to help predict when they will ovulate and be most fertile. 

Other methods, including observing cervical fluid, taking daily basal body temperature, and tracking periods can also help a woman identify when she is ovulating and what her most fertile days will be.

A woman’s monthly menstrual cycle is measured from the first day of the menstrual period until the first day of the next period. The average woman’s menstrual cycle is between 28 to 32 days, though some women have shorter or longer cycles.

Ovulation usually occurs between Day 11 and Day 21 of the cycle, counting from the first day of the last period. Ovulation:

• Usually lasts one day
• Can happen any time during this window
• Is not always the same day each month

Women who have shorter menstrual cycles are usually more likely to ovulate closer to day 11. Women with menstrual cycles on the longer side may ovulate occur closer to day 21.