My temperatures are really low and go below the range shown on the paper fertility charts. What should I do and what does this mean?
If you are using the paper fertility charts and your temperatures are consistently lower (or higher) than the range shown on the chart, you can modify the temperature range on the left hand side of the chart to suit.
Pre-ovulatory basal body temperatures normally fall between about 36.3 and 36.7℃. If you find that your temperatures before ovulation consistently sit below 36.3℃, you could have a low functioning thyroid gland (hypothyroidism), particularly if you experience other symptoms common to the condition.
Because thyroid problems can affect fertility, it’s important to get this possibility checked out by your doctor. See Step 3 of the Program for more information on thyroid dysfunction.
Alternatively, you may just have a thermometer that measures low. This can be checked out by trying a different thermometer (a cheaper thermometer may not have the same level of accuracy as a more expensive one).
If you do change thermometers however, make sure you do it at the start of a new cycle, so that you use the same thermometer through an entire cycle.