My friend is a 31 year old, soon-to-be MBA, yet she knows almost nothing about her cycle. From time to time before TTC I felt the same way and I had even more reason not to. When I was in college, I interned at Planned Parenthood and taught sex ed classes to inner city Los Angeles junior high school students. I knew all about preventing pregnancy, right? I was terrified of getting pregnant for 29 years of my life (well... maybe not as a child) and took birth control for 11 of those years. I understand why sex ed does what it does. Teenagers need education about preventing pregnancy. But the typical teachings also instill a lot of fear in girls (and women). I wish I had known more of the real story. I would have had exactly the same amount of sex, but would have protected myself by timing it and using protection against STDs and would therefore, have much less stress and fear about accidentally becoming pregnant.
I bet that many of you who choose to follow this blog do not need any education in this area. But the TTC newbies, and I'm sure some of your own friends, need this info, so give them the link!
We've all heard that the average woman's cycle is 28 days. But it is totally normal for your cycle to be shorter or longer than this. Mine is around 33 days (range: 28 to 40). Your cycle should be similar each month, but can be lengthened by stress or illness.
The first half (before ovulation) is called the follicular phase. This is the phase that may vary in length.
The second half is called the luteal phase. This is most commonly 14 days long although anything above 10 is ok. Your LP should be the same every month. (Mine is around 11, but varies - potentially an issue.)
Your hormones are constantly in flux throughout the cycle. OPKs and the Clearblue easy detect hormones that surge before ovulation.
From the fabulous Toni Weschler at TCOYF:
1. The woman's egg can only live up to 24 hours. Two or more eggs may be released over a maximum of 24 hours. So, in a vacuum, a woman is only fertile for about a day or two. But the man's sperm can live up to 5 days, so the combined fertility of the two individuals is about a week.
2. For a couple trying to get pregnant, the woman's fertile phase is as long as she has fertile quality cervical fluid, up through ovulation. That might be several days, or as few as one.
TMI? (Cervical Mucus):
Have you ever noticed something resembling egg-white when you (ahem) go to the ladies? Growing up, I always thought this was the actual egg coming out after I had ovulated. (In reality, the egg is MUCH smaller than this!) It's actually the most fertile type of cervical mucus, a great indicator that you are about to ovulate. Throughout the month your cervical mucus will go from dry, to sticky, to clear and watery, to egg-white, then back to dry. If your CM is not clear, watery, or egg-white-like, then you are not fertile. The other types actual kill sperm!
Tip: The rise in Estrogen causes the egg-white CM. Many women also experience some about a week after they ovulate. This is from the secondary Estrogen surge that you can see on the chart above.
This info is just scratching the surface, but I wanted to give it to you all in one place. It takes a ton of research to find reliable sources of information on your own. Hope it helps!