The previous sections of this class has explained in detail how the woman's menstrual cycle functions as well as the physical signs she can look for to detect her most fertile days. With this information the woman can use her vaginal mucous observations, changes in her cervix and possibly counting the days of her menstrual cycle to plan for some well-timed sex with her partner to conceive a baby. She can also use her temperature changes to detect ovulation (to confirm this has actually happened) as well as to support her other physical observations. The various physical signs are explained in depth in detecting the fertile days.

Therefore, if you remember that:

	A man's sperm can survive for up to 6 days in a woman's fertile mucous before she ovulates. But the most likely length of time they will survive to fertilise a mature egg is about 1 to 3 days before the egg is released. AND
	The egg can survive for 12 to 24 hours after it is released. Therefore it is still possible to conceive a baby if you have sex within this time after ovulation. However, you are more likely to conceive if the sperm are already present in the fallopian tubes (lying in wait - so to speak) before ovulation.