For those of us who have regular cycles (bleeding begins within the same three days each month} using a calender makes keeping a eye on where we are in our moon cycle each month easier. For those of us who have a more unpredictable cycle it is a bit more tricky.
First let me say that relying on a calender all by it self, estimating the day you will ovulate, is known as "the Rhythm Method" it is listed as a method of birth control with a 79% rate of effectiveness. Which means that many women get pregnant using this method.
I believe it is best used as a general guide, and combined with other techniques such as, mucus observation, observing cervical changes, using a basal thermometer and other methods of what I call fertility awareness.
Combined together these methods are safe and reliable. But they do require effort, many times on a daily bases, especially in the beginning when learning your personal rhythms.
When learning fertility awareness methods for contraceptive purposes, if you are sexually active it is very important to use a reliable source of birth control. Barrier methods are most common. Use this method of contraceptive as you learn fertility awareness methods, use it every time you have sex. If your cycle is regular (the same amount of days every cycle) it will be easier to determine when you are ovulating. After a few cycles, you should be able to get a feel for when you are ovulating. It is imperative that you use your contraceptive from the end of menstruation until you are positive ovulation has passed. If there is any doubt you are not ready to rely on fertility awareness methods, and you could make a mistake which very well could result in pregnancy. If your cycles are irregular, then it will take more time for you to learn the patterns of your fertility, and you must use extreme caution to avoid pregnancy. Read on to learn more.
Getting to know your Menstrual Cycle
Charting your Cycle