POAS ~ Fertility Info

Fertility Information
the "28-day" myth and other such nonsense!

Quick Abbreviation Guide

CD = Cycle Day (e.g. "CD 7")
DPO = Days Past Ovulation (e.g. "9 DPO")
DPIUI = Days Past Intra-Uterine Insemination (e.g. "12 DPIUI")
LP = Luteal Phase (the time after ovulation, before the next cycle begins)
W,D = Weeks, Days (e.g. "6w5d" pregnant)

I highly recommend* these books for learning more about general fertility as well as increased chance of pregnancy achievement and effective hormone/barrier-free birth control:*

"Everyone ovulates on Cycle Day 14 of a 28-day cycle."
--modern-day fairytale

If you're like most women, you've probably been taught that a woman's cycle is 28 days and she ovulates on day 14. Actually, this is a myth. These are only statistical averages, and length of cycle and day of ovulation vary widely among women. It even varies for each woman!

This is a 28-day cycle depicting ovulation on Day 14. It would be reasonable to use an HPT on the green days (10 DPO and later.)

A typical cycle, which begins with menstruation, is 25-36 days with ovulation typically occurring between days 12-18. However, it may not be that way for you! And even if your cycles are regularly the same length, you may not ovulate on the same day every cycle. The only way to determine when you have ovulated is to track your fertility signs by recording basal (waking) body temperature and/or gauging the changes in the quality of your cervical fluid, since it becomes more fertile (hospitable to sperm) nearer ovulation. Ovulation predictor urine tests can also help determine when you will ovulate. Generally, you are fertile up to 5 days before ovulation, since sperm can generally live in a woman's body for up to 5 days in fertile cervical fluid, and a couple days after the day of ovulation, because an egg can live up to 24 hours, and occasionally a second egg is released within 24 hours of the first.

This is a 28-day cycle depicting ovulation on Day 18. It would be reasonable to use an HPT on the green day (10 DPO and later.)

When a cycle varies in length, it is the time between menstruation and ovulation that varies. Less variable in length is the luteal phase, or the time between ovulation and the end of your cycle (the last day before your next period). The luteal phase typically lasts between 10 and 16 days, but it will not usually vary more than 1 or 2 days for each woman. So if, for example, your luteal phase is 11 days, it will usually always be 10-12 days. The luteal phase provides time for a fertilized egg, or embryo, to travel to the uterus to implant. The typical embryo implants 6-12 days after ovulation. Your body produces the hormone hCG when the embryo implants. hCG is the hormone detected by pregnancy tests. If no embryo implants, the uterine lining is shed, beginning the next cycle.

This is a 28-day cycle depicting ovulation on Day 12. It would be reasonable to use an HPT on the green days (10 DPO and later.)