Let's now explore this window further to determine just when was the optimum time.The egg once released use a lifespan of twelve (12)hours. The egg therefore, should be fertilized in this twelve- hour period for conception that occurs. The sperm conversely can survive around 5 days in the reproductive duct. A progesterone blood test is performed to discover how much of the progesterone hormone is in a sample of blood. This female hormone is produced whenever a mature egg is released from an ovary after a process generally known as ovulation. This hormone helps you to prepare the endometrium (uterine lining) to just accept the egg if sperm fertilizes it. If the egg goes without having to be fertilized, menstrual bleeding occurs and progesterone levels drop. This free monthly calendar tracks your cycle in a very quick and simple way. All you have to do is type in the date of your respective last period and the calendar does the remainder. Everything is color coded for simple viewing. Green displays fertile days, blue may be the present day, and red occurs when you are expected to get a period. This is all based on the cycle length and the date of the first period which you entered.