A short menstrual cycle will occur when a woman ovulates early in her cycle. If she does, she will have markers of fertility (i.e., either high monitor readings or high mucus ratings) earlier than usual (See example Short Cycle Chart). The electronic fertility monitor is designed for menstrual cycle lengths of 22-42 days in length. If you have 2 or more cycles outside of those lengths, please consult with your NFP nurse. For those using mucus monitoring please continue to follow the normal instructions for determining the fertile window and read the instructions below.
To manage short cycles due to early ovulation, you should:
Realize that you can ovulate early in any cycle.
Check for cervical mucus on the light and very light days of your menstrual cycle.
If high rated mucus is observed, consider those days as fertile.
Two or more short cycles, please contact your NFP nurse for a Life Style Assessment.
THE BEGINNING OF FERTILITY:
Fertility BEGINS on day 6 of the first 6 cycles.
After 6 cycles, fertility BEGINS on the earliest day of “peak” type mucus during the last 6 cycles minus 6 days or the first "high" mucus reading - whichever comes first.
THE END OF FERTILITY:
Fertility ENDS on the last “peak” day of cervical mucus plus 3 full days.
After 6 cycles, fertility ENDS on the last “peak” day of the last 6 cycles plus 3 full days, or the last "peak" day of cervical mucus plus a count of 3 full days - whichever comes first.
NOTE: If you know you fall into the short cycle parameters (<22 days) instructions for avoiding a pregnancy in the first six cycles is to consider yourself fertile until the end of the 4th day past the peak day.