This is a brief summary, for more details see other pages in this site and follow links I have included here. I put this together to be a quick reference of things you need to know. I have gone into greater detail elsewhere in the site. I put this together to help clarify some things, and to answer some commonly asked questions.
When charting your cycle, there are a few basics to know, and this will also help you understand what I'm talking about here in the site. Day 1 is the first day you bleed, the first day of your period. On the first day you begin to bleed mark your calender Day 1 and begin counting the days, I always mark the days right on my calender. 1,2,3,4,5.....etc. I have a 28-30 day cycle most months, though sometimes it varies. last month it was 24 days long. So I usually number my calender through day 28. I do this on the first day of every cycle, the first day of menstruation, a day I usually try to take it easy.
So the next time you bleed that cycle has come to a close. Lets say bleeding began on Day 27, that is 27 days from the first day of bleeding last period. Then the cycle starts over with Day 1 being the same day as Day 27. The cycle ends on the same day the new cycle begins. I hope that makes sense to all of you. I have written a page on charting your cycle, visit it for more in depth information.
Sperm can live inside you for up to 5 days, and depending on the individual, maybe up to 7 days.
An egg is capable of being fertilized for 24 hours, then begins to deteriorate.
Learning to tell when you will ovulate is the hardest part. Because sperm can live inside us for several days, the time between the end of the blood flow and ovulation is the most dangerous time to have unprotected sex if you want to avoid pregnancy.
It is pretty easy to tell when ovulation has occurred if you learn the signs. There are several methods you can use to determine when ovulation has occurred.
The basal thermometer tells you when ovulation has occurred, but does not tell you when it is approaching.
Learning how to read your mucus is a pretty reliable way to know when ovulation is coming, however, waiting until you see fertile mucus to use condoms is risky, and semen can affect the mucus. There are some natural family planning books out there that tell you at the first sign of mucus, you should start using protection, In my opinion, that may be too late, for me personally, there are cycles where I only have a day or two of mucus before the stretchy mucus appears, and there are times where I will only notice a small amount of clear stretchy mucus, just once, with no mucus before that or after that. It is important not to rely on mucus alone. I use mucus characteristics to confirm the passing of ovulation, using my calender as a guide. I rarely have unprotected sex after Day 7 and never after Day 9 (and if I have unprotected sex on Day 8 or 9 I always feel nervous, knowing should I ovulate early I could become pregnant. By not having unprotected sex after Day 7 (this decision is based upon the information I've gathered from charting my cycle) I feel safe, and have not been pregnant for more than 4 years.
After fertile mucus is positively identified, I always wait a few days, usually for my own peace of mind, I wait until Day 19 even if I have seen fertile mucus several days before. When the stretchy mucus has dried up, ovulation has probably occurred. If you are just learning to chart your cycle and identify fertility signals, during the first 3 months (if your cycles are regular) use protection the entire cycle, if your cycles are irregular, you should chart for a minimum of 6 months, before relying on FAMethods. If there is any doubt to whether you have ovulated, don't take any chances, use protection. I hate to see women get pregnant when learning FAM. I had to learn the hard way, don't take any chances.
Some women feel ovulation when it occurs, it could feel like a sharp pain, or some women experience a dull ache, it usually is felt in the lower abdomen, either on the right or left side. And will alternate sides each month. Most women do not feel ovulation occurring. This is good to let you know when ovulation has occurred, but does not give you warning to protect yourself against the sperm who can survive within our fertile mucus for 5 days or so. And sometimes fertile mucus is happening but since it come from the cervix it doesn't always make it down to the vaginal opening where we might notice it on the toilet paper.
There are two choices for help in determining when ovulation is occurring. First there is a basal thermometer. This is good for women who have a schedule, who wake up at the same time every morning. This is very good for women who have irregular cycles. Its main drawback, is that it gives you zero warning of approaching ovulation, it only tells you that ovulation has occurred.
For women who have regular cycles and/or who don't have a morning schedule, like myself, I don't rise at the same time every morning, using a plastic speculum was much more effective for me. I found it very reliable, extremely interesting, and a very enlighting experience. By observing my cervix I was able to tell when ovulation was approaching, when it was most likely occurring and watched the opening of my cervix (called the os) close. When it was completely closed again I knew ovulation was over and it was safe to have unprotected sex. For more information about cervical changes and observation.
I hope this helps to clarify some things, there is lots more information here so please look around.