What to start from and how to do the chart analysis on your own?

If you know any of the fertility awareness methods do not hesitate - try to designate all important information like fertile days, temperature levels, temperature shift and the luteal phase as well as fluid and cervix peaks. Try and see that this is not so difficult!

If you do not know the rules of fertility recognition do not worry – soon you will be able to analyze charts on your own, too! At first you must get to know the rhythm of your body and, above all, understand the ways of observation. You can also ask 28days experts for advice.


On your current cycle, or any other you want to analyse, choose the option Chart analysis from menu.

Choosing this option you start a form which contains fields to be filled in.

How to appoint fertility days?


Fertility days in a menstrual cycle – time in which it is possible to conceive. In other words during that time woman’s body creates a favorable condition for the sperm cells to survive in the reproductive tract. It is also the time of the egg cell maturation and egg release from the ovary i.e. ovulation. owulacji.

On the basis of the principles of a chosen fertility awareness method you can designate the last day of relatively infertile phase (pre-ovulatory) and the beginning of postovulatory infertility. After entering the relevant days of the cycle in the appropriate fields and accepting changes the red vertical lines will appear on the chart, between which the period of fertility would be assigned.

The last day of relatively infertile phase (pre-ovulatory) – this is the last day when the chance to conceive is slight. This phase can have different lengths in different cycles. The way of assigning it depends on the fertility awareness method used and your experience.

The beginning of post-ovulatory infertility – from this day a child’s conception is no longer possible. This period is characterized by a relatively constant length. The way of its designation depends on the chosen fertility awareness method used and your experience.

How to set the temperature levels?


To make the chart’s interpretation easier in some fertility awareness methods one or two horizontal lines are determined. They correspond to lower and higher temperature level (LTL & HTL). These levels can be marked only after observing 3 higher temperatures than the previous six, undisrupted temperatures.
Usually the line of the lower temperature level goes through the highest of the six temperatures before the temperature shift. The line of the higher temperatures level, as an auxiliary, should be automatically designed at 0.2 degrees (0.4 degrees if using Ferinheight) above the line of lower temperature level. The higher level is ALWAYS 0.2 degrees in Celsius (0.4 degrees in Ferinheight) higher then the lower level. For example – if the lower temperature level is 36.55 – higher is 36.75; when lower is 36.6 higher is 36.8 and so on and so forth. (example: 97.3 for the LTL and 97.5 for the HTL in Ferinheight).

When taking your temperature with the digital thermometer with two decimal places you should round the temperature to 0.05 Celsius degrees.

When you have any disrupted temperatures or lacks in measurement among last 6 lower temperatures you should skip the days and count them back as to have six undisrupted temperatures of the lower phase.

Each fertility awareness method has a set of rules for how to deal with disrupted temperatures both in a lower temperatures phase as well as after the temperature shift.

How to appoint the fluid and cervix peaks?


Marking the cervical fluid and cervix peak is very helpful when appointing the end of the fertile phase. The way of determining the peaks depends on the fertility awareness method used as well as individual feelings and observations.

The cervical fluid peak is determined retrospectively, i.e. on the next day when we observe the disappearance of fertile cervical fluid (depending on the used method). Then in the field the day of the cervical fluid peak you enter the number of the day before.
The peak of the cervical fluid + 3 days ends the fertile phase.

Features of more fertile mucus: - transparency, stretchy, watery (viscus), wetness, feeling of lubrication (slippery), the fluid resembles a raw chicken eggwhite.

Features of less fertile mucus: stickiness, looks lumpy, colours: white, creamy, yellowish, feeling of dampness or dryness.

The cervix peak should be also determined retrospectively. After observing the tendency to closing, hardening and lowering we recognize the preceding day as the cervix peak. Then in the field the day of cervix peak you enter the number of the day before.
The peak of the cervix + 3 days ends the fertile phase.

Features of cervix in the fertile phase is - softer, located above, opened.

Features of cervix in the post ovulatory phase is - harder, located lower, closed.

Important notice – the fluid and cervix peak do not have to appear at the same day.

How to appoint the luteal phase?


The luteal phase starts at the first day of temperature shift no matter if the cervical fluid has already disappeared or not.

Counting days of luteal phase allows you to predict the beginning of the next menstrual period (10-16 day after temperature shift), assume pregnancy (18 days), confirm pregnancy (21 days) and count days of the conceived child.

The luteal phase is the period of the corpus luteum (gland secreting progesterone) activity, from its development in the ovary till the atrophy before the next menstruation.

The correct length of luteal phase confirms the appropriate level of progesterone secreted by the corpus luteum, and any failures may provide a basis to test your hormones in a cycle. The luteal phase prolongation to more than 20 days confirms pregnancy.

How to appoint ovulation?


The day of the ovulation, indicated by the blue vertical line on a chart, may be appointed properly only on the basis of ultrasound observations. Ovulation tests and fertility symptom observations do not give you 100% certainty as to when ovulation occurred. Ovulation may occur up to 2 days before and 2 days after the temperature shift (including the second day).

How to appoint the temperature shift?


The temperature shift – the beginning of the higher temperature phase, lasting till the next menstruation (10-16 days).

To appoint the temperature shift you have to find three temperatures higher than the previous six, undisturbed temperatures. You enter the first of these higher temperatures and the program will number three following temperatures.
Important notice – numbering depends on the chosen fertility awareness method and the way of dealing with disrupted temperatures. In most of the methods the disrupted temperatures should be omitted.

Three or four days of temperature shift confirm the relationship between the cervical fluid and cervix changes, the end of fertility phase, the rise of the level of progesterone and indirectly ovulation.