When a woman ovulates, one of her ovaries releases a mature egg into the fallopian tube, where it can be fertilized for roughly 12 to 24 hours. This event typically happens once per cycle, around day 14 of a 28-day cycle, though the timing varies. The release itself is just one moment, but the hormonal shifts leading up to and following ovulation create a cascade of changes you can actually feel and observe.
The Hormonal Chain Reaction
Ovulation doesn’t happen spontaneously. It’s triggered by a sharp spike in luteinizing hormone, often called the LH surge. This surge causes the egg to release about 36 to 40 hours later. In the days before the surge, estrogen levels climb rapidly as the fluid-filled sac (follicle) housing the egg grows on the surface of the ovary. That rising estrogen is what sets off the LH surge in the first place, creating a tightly choreographed feedback loop.
These hormonal shifts do more than release an egg. Estrogen at its peak also raises levels of oxytocin, sometimes called the love hormone. The combination of high estrogen and oxytocin is likely why many women notice a higher sex drive right around ovulation. From an evolutionary standpoint, the timing makes sense: your body increases desire precisely when conception is most likely.
What You Might Feel
Some women feel a twinge or dull ache on one side of their lower abdomen around the time of ovulation. This is called mittelschmerz, a German word meaning “middle pain.” The discomfort may come from the follicle stretching the ovary’s surface just before rupture, or from the small amount of blood and fluid released when the follicle opens. It can last anywhere from a few minutes to a couple of days. Some women notice it every cycle, others only occasionally, and many never feel it at all.
Your body temperature also shifts, though not in a way you’d notice without a thermometer. After ovulation, basal body temperature rises by about 0.4 to 1 degree Fahrenheit. The increase is driven by progesterone, which the body starts producing in larger amounts after the egg is released. This temperature bump stays elevated through the rest of the cycle and only drops back down when your period starts (or stays up if pregnancy occurs).
Cervical Mucus Changes
One of the most noticeable signs of ovulation is a change in vaginal discharge. In the days before ovulation, cervical mucus is typically thick, white, and sticky. As estrogen rises and ovulation approaches, the mucus becomes wet, stretchy, and slippery, often compared to the look and feel of raw egg whites. This fertile-quality mucus usually lasts about three to four days, appearing around days 10 to 14 in a 28-day cycle.
The change isn’t cosmetic. That slippery consistency has a functional purpose: it creates a hospitable environment for sperm, making it easier for them to travel through the cervix and into the uterus. When the mucus is thick and dry earlier in the cycle, it acts more like a barrier.
The Fertile Window
Although the egg itself survives for less than 24 hours after release, the window for conception is wider than that single day. Sperm can live inside the reproductive tract for up to five days. This means the total fertile window spans about six days per cycle: the five days before ovulation and the day of ovulation itself. Having sex even several days before the egg is released can still result in pregnancy if sperm are alive and waiting in the fallopian tube.
This is why ovulation prediction methods focus on identifying the days leading up to ovulation, not just the day it happens. By the time you confirm ovulation has already occurred (through a temperature rise, for example), the most fertile days have passed.
What Happens Inside the Ovary
The physical release of the egg is more dramatic than it sounds. Over the preceding days, the dominant follicle swells to about the size of a small grape on the ovary’s surface. Enzymes break down the follicle wall layer by layer, dissolving the structural proteins holding it together. Eventually the wall thins enough to rupture, and the egg, surrounded by a cluster of supporting cells, is swept out.
Finger-like projections at the end of the fallopian tube, called fimbriae, move across the ovary’s surface to capture the egg and guide it into the tube. From there, the egg begins a slow journey toward the uterus. If sperm are present in the tube, fertilization typically happens within the first 12 to 24 hours.
After the Egg Is Released
Once the egg leaves, the now-empty follicle doesn’t just disappear. It collapses and transforms into a temporary structure called the corpus luteum, which begins pumping out progesterone. This hormone prepares the uterine lining to receive a fertilized egg by making it thicker and more blood-rich. Progesterone levels peak about six to eight days after ovulation, and the production is pulsatile, meaning it comes in bursts rather than a steady stream. Levels can fluctuate dramatically within the span of just 90 minutes.
If the egg isn’t fertilized, the corpus luteum breaks down after about 10 to 14 days, progesterone drops sharply, and the thickened uterine lining sheds. That’s your period. If fertilization does occur, the early embryo sends a hormonal signal that keeps the corpus luteum alive and producing progesterone until the placenta takes over, usually around the end of the first trimester.
This post-ovulation phase, called the luteal phase, is also when many women experience the mood shifts, breast tenderness, and bloating commonly associated with PMS. Those symptoms are driven largely by the rise and fall of progesterone, not estrogen, which is why they show up in the second half of the cycle rather than around ovulation itself.