Quick NFP Question


For those of you who practice the sympto-thermal method, I’m trying to set the date at which phase 1 ends and phase 2 begins, and I’m using the Doering rule - the earliest day of thermal shift, minus 7. The Doering rule asks for 6 cycles charted, but I am right now charting my sixth cycle.

Do you think it’s OK to set the end of Phase 1 according to that rule, even though I have only 5 (and not six) cycles fully charted? Do you think that’d decrease the reliability of the method much? My wife’s cycles are fairly consistent in their patterns, up to this point.

Any help appreciated!


I personally have extremely variable cycles… so any “rules” about counting days never worked for me (I’ve actually never heard of this “Doering rule” :confused: )

By its very nature, the sympto-thermal method relies on watching SYMPTOMS (not counting days) to determine what phase you’re in. Mucous and cervical changes should give you the best idea of when phase 2 should begin…

I’d just never (personally) rely on counting days… it would never be accurate for me.



Note I was asking about the rules for determining when Phase 1 ends, not Phase 2.

Doing that mostly requires some statistical information about the cycle. The Art of Natural Family Planning Fourth Edition includes 5 endorsed rules on how to make that determination: clinical experience, 21 day, 20 day, Doering, and last dry day. All but the last one involve counting days (in some sense or other) from previous cycles to figure out when phase 2 starts. After that, you are up to making sympto-thermal observations to determine when phase 3 begins and phase 2 ends.


I know what you meant… end of phase 1… start of phase 2…

I didn’t learn from the Art of Natural Family Planning, but I do have the book (I found it cumbersome to read, to be honest… so I haven’t read all the “rules”)…

In the way I was taught, the symptomatic observations for the end of phase 1/beginning of phase 2 are to monitor mucous and cervical changes… as soon as you notice increased mucous (this date could vary from cycle to cycle and is definitely variable for me, personally) you would determine the start of phase 2.

This observation of mucous and cervical changes continues throughout all of phase 2 to determine peak ovulation day… and then the thermal shift is used to verify the end of phase 2/start of phase 3.

Hope that helps!


Thanks Em, I believe that’s the same as the “last dry day” rule in Art of NFP. The only problem is that it’s the least reliable (statistically as perfectly used, as well as frequency of mistakes) of any of the phase 1 rules, and you have to have charted at least one year before trying that out (if I remember correctly).

The Doering rule is more reliable; it subtracts seven from the earliest thermal shift day recorded (for my wife, that’s 18 minus 7; so day 11 ends phase 1 and would be safe, all other things being equal). The only problem is that Doering requires six cycles charted, and we have only five done - hence the question.


I am a new NFP user of the sympto thermal method. (on charted cycle 4 right now)

I just wanted to mention that from how I understand the book, don’t downplay the importance of last day dry. You can use any of those other methods to determine the end of phase I, but if mucas returns before you calculated the end of phase I to be, you count the last day dry as end of phase one.

So, if by Doering, day 11 is your end of phase I, but mucas returns on day 9, then day 8 is the last day of phase I and phase II begins on day 9, regardless of calculations for Doering (or any other) rule.

Oh, and I want to say how great I think it is that you are trying to be so active with your wife in learning NFP.:thumbsup:


It really depends on how consist your wifes cycles have been the last 5 cycles. IF she is exactly the same every month and all the symtoms appear to be doing the same thing then sure use the rule. But you always have to be open to new life when you want to fudge the rules. I suppose 6 months is a mostly arbatrary # in which most couple would have a good enough idea of how their bodies work and can accurately see what her normal cycle looks like. If she is at all irregular i would wait longer then 6 months. But hey babies are wonderful things!!!


Like I mentioned, I was never taught the alternative “rules”… and started from my first cycle using the symptomatic method… and 7 years into using NFP (minus my pregnancy times) we’ve never had any issues with that method.

Actually, it’s a rather important method to get good at for detecting oncoming ovulation after having a baby (postpartum NFP is the most difficult while breastfeeding)… and I was able to detect my first ovulation without a doubt after both my previous pregnancies! You won’t have any of the “counting” rules available postpartum, so I do highly recommend looking into this “last dry day” rule before becoming pregnant!

I would have assumed that this would have been a very conservative method, actually… looking at the QUALITY of the mucous, not just the quantity. The mucous changes consistency from “sticky-thick” to “slippery-stretchy”… if you conservatively abstain from the moment you notice “sticky-thick” then you’re being more than conservative!

Good luck!

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