Estrogen
Estrogen begins surging through the body roughly three or more days before ovulation. This causes the cervical fluid to be clear, thin and stretchy*. This type of cervical fluid is referred to as egg-white cervical mucus" or "ewcm. EWCM offers the best mode of travel for the sperm to get to the egg.
The high levels of estrogen prompts the release of luteinizing hormone (LH). The surge of LH causes the egg to actually come out of its follicle. The time period from which ovulation occurs and a woman's menstruation is called the luteal phase (LP). The average length of time during LP is 12 to 16 days long. The LP, however, can be longer or shorter. An LP shorter than 10 days is considered deficient in progesterone, and is unable to maintain a pregnancy. There are measures to increase the LP, such as hormone therapy and/or herbal and vitamin supplements. No matter what day a woman ovulates, she can always tell approximately what day her menstrual cycle will begin, or what day to take a pregnancy test.
With the collapse of the follicle, a corpus luteum forms.
Progesterone
The corpus luteum begins producing progesterone - the hormone that helps maintain the uterine lining long enough for a fertilized egg to implant. Progesterone is responsible for raising the basal body temperature, also known as the "warm hormone." If a woman is charting her temperatures, she should be able to tell that she had ovulated by an upward shift in her daily basal body temperature. A drop in progesterone signals the body to begin shedding the uterine lining, thus bringing on menstruation.
Stress and Your Health
If pregnancy is the goal, its extremely important to have intercourse around the time of ovulation, preferably right before, or during, ovulation. Sometimes a womans body can prepare for ovulation and release all the right hormones, and stress will halt the process. Vacations, moving, company or anything that causes undue stress, can delay ovulation until the woman is at peace and relaxed again.
The role of hormones combined with the womans state of health - sick or stressed, determines when and if ovulation occurs.
Sometimes ovulation does occur on day 14, but this is, by far, not the rule. Because the different elements that bring about ovulation can be varied or interrupted, its safe to say that ovulation can occur at any point in the cycle, and not the day 14 that so many people once believed.