pozhadujsta, tell or say as to count up correctly period between monthly...

[a]

pozhadujsta, tell or say as to count up correctly period between monthly

[Corax]

The question is not absolutely clear.
If wish to learn or find out the period of an ovulation - take basal temperature.

[child]

Nadja you noverno wished to learn or find out as it is considered a cycle. From the first day monthly till first day of the beginning of the following monthly.