Natural Family Planning (NOT to get pregnant, lol) Fertility Awareness: Natural Family Planning (NFP) "Fertility awareness or Natural Family Planning is a method of birth control that does not use any drugs or devices. It combines the calendar/rhythm method, the basal body temperature method, and the cervical mucus method."
Pregnology is all about pregnancy dates and numbers. You can calculate your due date, how far you are along in your pregnancy, calculate your most fertile days, calculate when you can take a pregnancy test, calculate in which pregnancy month, week and trimester you are.
Lost track of how far along you are? This chart can tell you how many weeks and days you are for every day of your pregnancy. I found out that I will be exactly 20 weeks pregnant on Christmas Day. Fun and informative tool.