The “textbook” cycle — why this standard approach rarely works
Many resources on menstrual education assign specific cycle days to each phase. Something like this:
- Menstrual phase: from day 1-7 (approx.)
- Preovulatory phase: from days 7-11 (approx.)
- Ovulatory phase; from days 12-16 (approx.)
- Premenstrual phase: from days 16-28 (approx.)
⚠️ But this standard approach rarely works! ⚠️
And there are a few reasons for that:
1. Not everyone has a 28-day cycle
This is, in fact, one of the biggest myths around the cycle.
A healthy cycle is anything from 24-35 days. 28 is just the average between 24 and 35 and is used to understand the cycle in general terms. Your cycle could be shorter or longer than 28 days, and it’s OK.
What is important to know is that if it’s shorter than 24 or longer than 35 days, or if you are not ovulating, it’s a sign of an imbalance.
2. The length of each phase varies from person to person and from cycle to cycle.
If you have a regular cycle, figuring out the length of each phase will be easier for you.
However, some people have irregular cycles. Mine, for example, sometimes lasts 27 days, sometimes 33, sometimes up to 45 (this is due to PCOS). And, of course, if the cycle length varies every month, so will the phases, specifically the preovulatory phase (more on this in a moment).
3. Several factors can affect the length of the cycle.
Whether you are regular or not, you should consider that things like stress, illness, jet lag, dietary changes, etc., directly affect the length of your cycle.
This makes a lot of sense from a biological point of view. When your brain senses that you are in stress or danger, it signals your ovaries that it’s not a good time to make a baby. Consequently, ovulation is delayed for a few days or even weeks, which lengthens your cycle. It’s not exactly that your period is late but ovulation is, and in consequence, your period.