How BBT Charting Could Help 

You Get Pregnant

Fertility health can be diagnosed by assessing your menstrual cycle health.

If your cycle shows areas of imbalance, it could well be impacting your ability to fall pregnant and have a healthy pregnancy.

Being able to identify the areas of imbalance in a cycle can be achieved to a deeper degree with BBT charting.

BBT charting reflects the general health and function of your menstrual cycle, and is therefore an ideal tool to assess your fertility health and your ability to have a healthy pregnancy.

What is BBT Charting?

‘BBT’ stands for Basal Body Temperature, and it’s a method that is based on measuring your resting (basal) body temperature once a day, first thing in the morning and then recording it on a chart.

This temperature is a unique resting temperature that gives feedback on how well your body is working. It can show you whether there are any underlying functional health issues present that can’t be seen via day-to-day symptoms.

Your resting body temperature changes significantly throughout the 2 key phases of your cycle: 

  1. The Follicular phase – from CD1 (cycle day 1) of menstruation through to ovulation.
  2. The Luteal phase – from the 1st day after ovulation through to the last day before menstruation begins.

Once you’ve taken your temperature each morning you log it on a chart (there are lots of free apps available) each day, and over the course of the cycle you will start to see a pattern developing. 

This monthly pattern of temperatures gives you feedback on what’s going on, and it can identify any deeper fertility health or cycle issues that could be stopping you from getting or staying pregnant.

How BBT Charting Can Help You

BBT charting enables you to track the functional aspects of your cycle and fertility health, whilst also identifying your fertile window and ovulation. 

Knowing your fertile window and when ovulation occurs, is key to optimising your chances of getting pregnant.

Much more efficient than Ovulation Predictor Kits (OPK’s), BBT charting allows you to actually confirm that ovulation has taken place. 

OPK’s do not do this. 

They only pick up hormone levels (usually LH, but some also measure Estradiol) to predict when ovulation might happen. 

It’s also possible to release these hormones and not ovulate. 

If you have intercourse relying solely on an OPK, and it’s wrong, then you will have missed your ideal chance of conception for the month and pregnancy won’t happen.

OPK’s are therefore often misleading when used alone.

Comparatively BBT charting shows you an increased temperature range that can only happen after ovulation, and so it is able to confirm that ovulation very likely happened and exactly when.

Collectively over the course of a few charts you will be able to clearly see your typical days of ovulation, and then plan ahead to ensure that sexual intercourse is carried out at the right time. 

Using an OPK as a predictor, and then a BBT chart to also predict and confirm, is the best solution. 

BBT charting can also identify functional cycle and fertility health issues that may not be seen through basic medical tests, that could be stopping you getting or staying pregnant.

Identifying Your Fertility Health Balance

Chinese medicine has assessed fertility health, for over 2300 years [1], by observing the menstrual cycle.

Viewing BBT charts through the eyes of Chinese medicine can take you even deeper into identifying your health balance. The monthly temperature patterns will allow you to see the root of your fertility health, and in many cases also identify the reason for your delay in getting or staying pregnant.  

Throughout 25 years of reviewing more than 50,000 charts with thousands of people worldwide, I have seen the power of charting when it’s used correctly.

As is often the case in the western world, BBT charts are not interpreted to their fullest degree, and people sadly waste time charting in a way that just causes stress and no guidance or answers.

Hopefully I can help you avoid that, and instead help you to identify some important aspects of your health balance that will positively support you. 

With a bit of practice I know that charting will help you reach a point of clarity so that you know exactly what your cycle is doing, which will allow you to take positive action towards optimising your fertility health.

There are some foundational rules of BBT charting that I’ll share with you here, but there are also lots of things ‘out there’ that are quite frankly just myths. And they mostly cause a lot of unnecessary stress when charting.

Some of the Key Benefits of BBT Charting:

  1. Identify what’s working well in your body
  2. Identify what’s not working well, and how this is impacting your fertility health
  3. Always know where you are in your cycle
  4. Can see when your typical date of ovulation is to time intercourse more precisely
  5. Know the stages of your cycle to alter your diet, lifestyle etc to support it
  6. See whether any areas of your cycle and health are generally out of balance
  7. Track the results of treatment on your health by watching the pattern changes
  8. Predict when your period is due, so that you know when it’s sensible to do pregnancy tests or not

The 2 Phases of Your Cycle

As I mentioned above, for the purposes of BBT charting we want to work with your cycle in 2 distinct phases as follows:

1. The Follicular Phase – the ‘cool’ temperature phase

At the end of your cycle (just before menstruation starts) your Progesterone level will drop. This drop in hormone triggers the start of bleeding, and you begin a new cycle.

During menstruation your Progesterone, Estrogen, LH, and other hormone levels drop to their baseline levels, which should cause your body temperature to drop to the lowest level in your cycle. 

Immediately after menstruation you will start to release FSH (Follicle Stimulating Hormone), which causes your follicles to grow and release estrogen. The increase in Estrogen keeps your BBT low until you reach ovulation.

2. The Luteal Phase – the ‘warm’ temperature phase

After ovulation has occurred your BBT will immediately rise.

It should then remain elevated for up to 14 days, if you are not pregnant, at which time your menstruation will begin again and the temperature will drop back down again.

If you are pregnant your BBT will stay elevated for the next 9-months, until you give birth.

So to summarise: In the Follicular Phase your temperature is cooler, and in the Luteal Phase your temperature is warmer – as long as your body is working well.

When you start BBT charting you should be able to see these two phases quite easily in your chart. If you cannot see this, don ‘t worry, in time you’ll be able to identify why.


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How to BBT Chart

To start BBT charting you will need:

  1. A reliable thermometer
  2. An app where you can record the temperature. You can use paper, but apps are easier and portable and can store lots of other info too. I currently recommend the app as it’s free.

Below is what a blank chart looks like. 

I’ve added one temperature (blue dot) so that you can see the layout of the chart. 

The side shows the temperature (you can choose centigrade or fahrenheit in your settings). 

The top shows the date. The bottom shows the cycle days.

How to Measure Your Temperature:

1. Each day as soon as you wake up, take your temperature orally before getting up, drinking or speaking. 

Do not get out of bed until it’s complete. 

Some people like to do vaginal temps, which is fine, but orally works well too and is what I recommend.

2. Try to take the temperature as close to the same time each day as you can. 

The further apart you take the temps each day, the more changes in temps you will see and this will not give an accurate picture.

Once measured, record it on your BBT chart and then start your day as usual.

Make sure that you record the temperatures on the right day of your cycle each time. For reference, CD1 (cycle day 1) is always when you start to properly bleed at the start of menstruation.

Below is a completed chart for reference.

You can see the lower/cooler temperatures from menstruation to ovulation.

You can also see the higher/warmer temperatures from ovulation to the end of the cycle.

The point at which the temperature increased is the first day after ovulation – typically called 1 Day Post Ovulation (1 DPO).

CD15 was the actual day of ovulation, and CD16 was the first day post ovulation (1 DPO).

This is a textbook chart to clearly show the 2 phases, and point of the fertile window and ovulation, but please bear in mind that most charts go up a down a little each day.


Things to Consider:

1. Do not use an external skin based thermometer or wrist band. They measure a much lower body temperature and are not accurate for BBT charting purposes.

2. It’s suggested to have 3-4 hours of solid sleep before you take your temperature. 

However if this isn’t possible due to waking earlier, don’t worry and just take it at the same time of day as usual. 

The FertilityFriend app allows you to note the time of taking each day, and it highlights any days that you take it earlier or later.

3. Disturbed sleep, alcohol, going to bed late, being overly warm or cold can in many instances affect your temperature reading. There’s no need to worry about this, but just bear it in mind if you see unusually higher or lower temperatures in the BBT chart pattern. 

4. If you wake up much earlier than normal just take the temp at the usual time, and not earlier – but you must stay in bed to do this – don’t get up before temping.

5. Record any unusual events that might have altered your temperature in your BBT chart, so that you have this info for future reference.

6. At weekends I would suggest to take your temperature when you naturally wake up, and not set an alarm to take the temp. This gives a little break each week. The only time I would suggest against this is if you are at the point of ovulation, in which case you will want to know if and when it occurred.

7. BBT charting should be a relaxed approach to measuring temperatures and should not cause you stress.

Try not to focus on, or stress about, individual temperatures.

We are looking for patterns over the whole month, and temperatures will go up and down within each phase, which is totally normal. 

If used properly, in a relaxed way, the BBT chart can literally become your’ best buddy’ as it will show you any areas that need support to get you closer to your goal of having your baby.


If you’d like free support on understanding your BBT charts, and how to make health changes to optimise your fertility health, join me in my Facebook group:







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