I like to separate the menstrual cycle into 4 parts. The
first part is menses and should be fairly consistent from cycle to cycle. After
menstruation is the follicular phase where your body prepares for ovulation.
The length of the follicular phase can vary from month to month, which is what
makes your longer or shorter some months. The follicular phase ends with
ovulation, which is followed by the luteal phase. The luteal phase is where
implantation would occur, and the length of the luteal phase is consistent from
cycle to cycle, so once you confirm that ovulation has occurred you will know
when your period will arrive.
There are several ways to track your cycle to know when
you’ve ovulated. The book “Taking Charge of Your Fertility” as well as the
tutorials for the app Fertility Friend provide a very good explanation of what
signs your body gives you that ovulation is approaching. Cervical mucus, cervix
position, and ovulation prediction kits can give you an idea that your body is
gearing up for ovulation, but the only way to confirm ovulation (besides being
monitored by ultrasound) is to track your basel body temperature. After
ovulation there is a sustained rise in your basel body temperature, caused by
progesterone.
This past cycle I had a positive ovulation test and fertile
cervical mucus leading up to cycle day 17, and then my temp rise on cycle day
18, confirming ovulation on cycle day 17. My luteal phase is 10-11 days long so
I expected my period on cycle day 27 or 28. I usually have a temperature drop
the day my period arrives. Cycle day 27 arrived and no temp drop. Cycle day 28
and no temp drop. Cycle day 29, no temp drop. I took a test on cycle day 29 and
it was negative. I was spotting so I was confident that I was not pregnant, but
I couldn’t be sure until my period arrived. I was sure of my ovulation date and
3 days late and had a glimmer of hope that maybe, just maybe, something had
finally worked, but no, 4 days after my period was expected it arrived. Cycle
23 now.