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Charting your Fertile Window 101: Part One


Charting your menstrual cycle is an effective way to track your fertile window. It’s low cost, there are no tests or blood draws needed, it gets you in touch with your body and helps to better time intimacy.

Charting can help detect obstacles or areas to improve that can hinder fertility, such as late ovulation, anovulation, infertile cervical fluid, and miscarriage occurrences. It can also help clue us in to potential hormonal imbalances such as low progesterone and hypothyroidism.

Okay, so how do we do it? There are a couple of pieces that together give us a good picture of what’s going on.



Oral Basal Body Temperature (BBT):

What it is:

This is your temperature taken upon waking in the am. It needs to be taken at the same time every day, before you get up and move around.

What you need:

- A BBT thermometer. These thermometers cover the normal range of temperature, (as opposed to the fever temp range) and have a higher specificity. This is important because temperature only increases about 0.2 to a full degree.

- An app or temping chart paper to record on

What it tells you:

Typically, body temp is pretty consistent before ovulation, and spikes after ovulation. This is because progesterone, which is increases after ovulation, causes an increase in temperature.

Charting tells you:

- whether ovulation is occurring

- when ovulation occurs, which can help time intimacy in the next cycle

- the length of the luteal phase (second half of cycle), which needs to be long enough to allow for the egg to implant

- whether pregnancy has been achieved

- dates of conception/ predicted due date if pregnancy occurs

- whether ‘infertility’ is really recurrent miscarriage.

Tips: Most BBT save your readings, so on the weekend you can take your temp when you alarm goes off, and roll over to go back to bed. You can record the reading on your chart/app later.

Charting for a few months is ideal to see whether cycles and ovulation are consistent, which can then help predict the fertile window. As informative as BBT is, it is not effective alone! BBT confirms ovulation occurred but at that point, the fertile window has passed. Using this information together with other signs that we will cover in Part Two is the best way to chart accurately.


Written by: Faaria Karim (ND, USA. BC license pending)

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