Basal body temperature

Ovulation, also known as the third phase of menstruation, usually happens in the middle of your menstrual cycle. So, if you have a 28-day cycle, you should ovulate on day 14. The pituitary gland releases a heavy surge of LH (L-H), the luteinizing (LOOT-in-eye-zing) hormone. This increased hormone level is what home ovulation kits can detect. Within 24 to 36 hours of this surge, the follicle will rupture, releasing the matured egg to the fallopian tube. The remainder of the ruptured follicle recedes back to the ovary and begins to secrete progesterone. This hormone stimulates an increase in the blood vessels in the lining of the uterus so no more eggs will develop. Progesterone also makes your basal temperature increase approximately a half of a degree. Since this is the time the egg is released, this is your most fertile time. To maximize your chances of conception, experts recommend having intercourse immediately prior to ovulation or the day it begins.