Ovulation and the Menstrual Cycle

Ovulation basics

When you ovulate, a mature egg is released from the ovary and moves into the fallopian tubes, where it is available to be fertilized. If the egg is not fertilized, the lining of the uterus, which has thickened to prepare for fertilization, will be shed through menstruation.

Knowing when you’re due to ovulate will help you prepare and plan, which will increase your chances of achieving a successful pregnancy.

When Does Ovulation Occur?

Ovulation can occur at different times in a woman’s menstrual cycle, depending on her cycle’s length. The average menstrual cycle, counting the first day of heavy flow as Day 1, is usually 28 to 32 days. Women with a 28-day menstrual cycle typically ovulate 13 to 15 days after the start of their last period.

What Happens During Ovulation?

Right before ovulation, women experience a luteinizing hormone (LH) surge, which is linked to ovarian hormone production and egg maturation. Within 24 to 36 hours of an LH surge, a mature egg will be released (or ovulated) for fertilization. An egg is available for fertilization for 12 to 24 hours after ovulation. It will disappear after 24 hours if it is not fertilized.

On the other hand, sperm can live in the body for 3 to 5 days, making the total fertile window for most women around 5 to 7 days. This means you can get pregnant from intercourse that occurred either just before or just after ovulation.

Physical Signs of Ovulation

There are several physical signs that may let you know when you are about to ovulate:

  • increased cervical mucus and change in texture to a white, stringy consistency. This creates a healthy environment through which sperm can travel.
  • light spotting
  • cramping
  • abdominal bloating
  • breast tenderness
  • increased basal body temperature (BBT). Approximately 1 to 2 days after the LH surge, your BBT should increase about 0.4 degrees Fahrenheit. This increase in temperature remains for approximately 10 to 14 days.

What happens after ovulation?

If the egg is not fertilized, the lining of the uterus, which has thickened to prepare for fertilization, sheds through menstruation. The first day of heavy flow marks the first day of your next cycle, and the process begins again.

Dr. Taraneh Gharib Nazem is Senior Fellow in Reproductive Endocrinology and Infertility at the Icahn School of Medicine at Mount Sinai/Reproductive Medicine Associates of New York. She is a board-certified Obstetrician Gynecologist. Dr. Nazem completed her residency in Obstetrics and Gynecology at the New York University School of Medicine, where she was elected administrative chief resident and graduated with the Robert F. Porges Honor Resident Award, for outstanding performance.