Pregnancy occurs when a man’s sperm and a woman’s egg join. A woman’s ovaries hold the eggs that are released, one about every 28 days. The egg is usually released about 14 days after the start of a woman’s menstrual period. Since sperm can live approximately 3 days and women may ovulate at different times, a woman is typically most fertile 10-17 days after the first day of the last menstrual period.
As the egg is maturing in the ovary, the uterine lining is thickening preparing a healthy environment. Fertilization is caused when the man’s sperm meets with the egg. If the egg is fertilized by a man’s sperm, it travels down the fallopian tube into the uterus where it is implanted in the wall of the uterus and begins to develop into an embryo. If the egg is released and not fertilized, the lining is shed, causing menstruation.
