NFP temperature reads slightly off


#1

I recently restarted NFP charting. It’s freezing here, so I always warm the thermometer up in my hands before taking my morning temp. Lately, I started taking my temperature twice in a row and noticed a 0.2 jump in my temperature. (For example, today’s first temp was 97.74, the second temp was 97.92.) My NFP book (Taking Charge of Your Fertility) says that my temp shouldn’t jump that much in the first five minutes of waking, so I’m wondering:

  1. Am I doing something wrong?
  2. What can I do to ensure an accurate read on my first temp so I can stop taking a second temp?

Thanks!


#2

What kind of thermometer are you using? (digital or analog/mercury?)
Why are you warming it up? (for your comfort or for accurate readings?)
How are you taking your temperature? (in your mouth or vaginally?)


#3

Have you tried temping vaginally? This made a big difference for me as my temperatures fluctuated greatly due to my mouth breathing. I’m sure it might help with fluctuations due to external temperature variations. Yeah, it’s a pain, and mouth temping is way easier, but a girl’s gotta do what a girl’s gotta do. :wink: It takes the same amount of time, just a little more inconvenient. :o

Hope this helps! :thumbsup:


#4

[quote="prolifewife, post:3, topic:181889"]
Have you tried temping vaginally? This made a big difference for me as my temperatures fluctuated greatly due to my mouth breathing. I'm sure it might help with fluctuations due to external temperature variations. Yeah, it's a pain, and mouth temping is way easier, but a girl's gotta do what a girl's gotta do. ;) It takes the same amount of time, just a little more inconvenient. :o

Hope this helps! :thumbsup:

[/quote]

Yup! This is my suggestion and experience as well! :thumbsup:


#5

I’m using a digital Samsung Healthy Living thermometer (I believe it was the one displayed alongside the book at the Catholic book store.)

I’m warming it up because my bedroom is between 62 - 65 degrees in the morning. For cold bedrooms, my NFP book recommends warming the thermometer between your fingers for a few seconds to avoid inaccurate temps.

I’m taking my temperature orally, in part because I am also taking temps while menstruating to try to re-establish the habit. The last thing I want to deal with at 630am is a menses mess! :blush:


#6

Sorry to jump on your thread here, but I had a question. I just started charting too (still need to get a book though, I'm going off online instructions) and I had a question about the method of temping. This might sound stupid :blush:, but if you do it vaginally, is there a certain spot you have to make sure it gets to? I know the directions for the mouth say to put it in one certain area under your tongue for the most accurate reading. So would you have to be really close to your cervix if you do it vaginally or just make sure it gets in there? :confused:


#7

Just as far as you can comfortably (relatively speaking, yeah, it’s gonna feel a little uncomfy :p) place the tip inside. Don’t try to place the whole thermometer inside you! First of all, ouch! Second of all that could damage the thermometer. Also cleaning the tip after each use helps prevent bacteria from getting where it doesn’t belong. :wink: Follow your thermometer’s specific instructions on cleaning. Trust me the accuracy and consistency of results of vaginal temping far outweighs the added inconvenience. :thumbsup:


#8

[quote="Augusta_Sans, post:5, topic:181889"]
I'm using a digital Samsung Healthy Living thermometer (I believe it was the one displayed alongside the book at the Catholic book store.)

I'm warming it up because my bedroom is between 62 - 65 degrees in the morning. For cold bedrooms, my NFP book recommends warming the thermometer between your fingers for a few seconds to avoid inaccurate temps.

I'm taking my temperature orally, in part because I am also taking temps while menstruating to try to re-establish the habit. The last thing I want to deal with at 630am is a menses mess! :blush:

[/quote]

You can vaginally temp even during menstruation. Just follow your thermometer's instructions for cleaning after temping. Again the accuracy and consistency of results far outweigh the inconvenience. :thumbsup:


#9

[quote="prolifewife, post:7, topic:181889"]
Just as far as you can comfortably (relatively speaking, yeah, it's gonna feel a little uncomfy :p) place the tip inside. Don't try to place the whole thermometer inside you! First of all, ouch! Second of all that could damage the thermometer. Also cleaning the tip after each use helps prevent bacteria from getting where it doesn't belong. ;) Follow your thermometer's specific instructions on cleaning. Trust me the accuracy and consistency of results of vaginal temping far outweighs the added inconvenience. :thumbsup:

[/quote]

Great thanks! Next question is, would the plastic thermometer covers you can get (to reduce the need for washing all the time) alter the temperature too much?


#10

Alright, you convinced me to try it. :) I'm going to switch to vaginal temps tomorrow (day 3 of my cycle). I'll try doing a double-read to see if it's still jumping around so much.


#11

This thermometer is only a few years old, but it's been subjected to sub-zero temps (forgotten in the car once or twice). Is it possible that threw it off?

Six oral temps in succession:
98.38
98.47
98.42
99.33
98.48

Vaginal temps in succession:
98.81
98.83
98.84
98.85
98.88
98.89
98.91
98.92
98.93
98.95

It's definitely more consistent vaginally, but it took TEN attempts to warm the thermometer up enough to stop changing with every single read. I find it hard to believe my temp is skyrocketing at this rate (it's 1 in the afternoon here, and I'm just laying on my bed.)


#12

Great! :smiley: Now don’t be surprised if you get a temperature spike tomorrow. That’s natural with switching to vaginal temping. You are not supposed to change between the two. All temps for a cycle should be either vaginal or oral. But since you are on CD3 you should be fine to make the switch. But I would erase your first three days of temps and fill them in with your first vaginal temp recording. So if your vaginal temp for tomorrow reads 98.5 (or whatever) then record 98.5 for CD 1-3 also. This is only safe to do because you are so early into the cycle. If you were much farther along CD6 or greater I’d say to stick with oral until your next cycle then vaginal temp at the start of the next. :wink:


#13

Thanks, prolifewife! I edited my previous post while you were responding. Is this temp fluctuation normal?


#14

The sub zero temps could be an issue. Many thermometers have product cautions. I do believe temperature extremes are included.

But even with a perfectly working thermometer you won’t get the same temps in a row. Also it is daytime now, you’ve been (unless you are a nightshift worker) up for awhile. Your temperatures will be much higher than your basal body temps. That’s why you are supposed to take your temps first thing in the morning, before you even get out of bed. The slightest movements can throw your temps for a loop. This could explain the variances in the temperatures you just took too. :wink:


#15

I'm surprised your thermometer has a 'hundredths place... most don't!
Either way - the fluctuation is ~0.2degF orally and ~0.1degF vaginally in your little experiment... really, in the grand scheme of things, this isn't that bad. When you chart your temperature you're looking for an elevation at a particular time. You take your temperature through phase 1 & 2 just to establish a baseline - it doesn't have to be perfect. You know WHEN your temperature should start to rise (when your mucous and cervical position signs start trending away from fertile after ovulation), and that temperature rise should be AT LEAST 0.4degF and sustained for AT LEAST 3 days... rarely, have my sustained elevated temperatures been JUST 0.4degF - usually they range up to ~0.8degF. So my point is that this fluctuation (~0.1-0.2degF) is just in the noise... you should still be able to detect a significant temperature rise correlating with your other signs to ensure that you're safely into the infertile luteal phase...

HTH!


#16

[quote="Augusta_Sans, post:13, topic:181889"]
Thanks, prolifewife! I edited my previous post while you were responding. Is this temp fluctuation normal?

[/quote]

In my experience 0.1-0.2 degF is normal fluctuation... :)


#17

[quote="prolifewife, post:14, topic:181889"]
Also it is daytime now, you've been (unless you are a nightshift worker) up for awhile. Your temperatures will be much higher than your basal body temps. That's why you are supposed to take your temps first thing in the morning, before you even get out of bed. The slightest movements can throw your temps for a loop. This could explain the variances in the temperatures you just took too. ;)

[/quote]

I know. Both sets of temps were taken around 1 in the afternoon, not for NFP purposes but for "is my thermometer broken?" purposes. :)

[quote="Em_in_FL, post:15, topic:181889"]
I'm surprised your thermometer has a 'hundredths place... most don't!
Either way - the fluctuation is ~0.2degF orally and ~0.1degF vaginally in your little experiment... really, in the grand scheme of things, this isn't that bad. When you chart your temperature you're looking for an elevation at a particular time. You take your temperature through phase 1 & 2 just to establish a baseline - it doesn't have to be perfect. You know WHEN your temperature should start to rise (when your mucous and cervical position signs start trending away from fertile after ovulation), and that temperature rise should be AT LEAST 0.4degF and sustained for AT LEAST 3 days... rarely, have my sustained elevated temperatures been JUST 0.4degF - usually they range up to ~0.8degF. So my point is that this fluctuation (~0.1-0.2degF) is just in the noise... you should still be able to detect a significant temperature rise correlating with your other signs to ensure that you're safely into the infertile luteal phase...

HTH!

[/quote]

VERY helpful to know that my thermometer goes to a greater level of detail than most, and that a .14 fluctuation isn't a big deal. :) I went through my old charts (2006-2007) and you're right--usually my ovulation was marked by 0.4 - 0.8 temperature increases, which means a .14 fluctuation isn't a big deal. Whew! I am going to stick with vaginal temps since it seemed a little more consistent and I won't have to worry about keeping it in the perfect position in my mouth, etc. I'll report back if I have more problems! :)


#18

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit www.catholic.com.