Every day, your body is quietly working behind the scenes, going through beautiful, complex cycles that either prepare for or support pregnancy. For anyone trying to conceive (TTC), understanding ovulation and your menstrual cycle isn’t just “nice to know” — it’s essential. After all, there can be no pregnancy without ovulation.
So, let’s break down the menstrual cycle— no jargon, just what you actually need to know.
What Exactly Is a Menstrual Cycle?
Your menstrual cycle starts on the first day of your period (Day 1) and ends the day before your next period begins. The number of days in between is your cycle length.
For some women, this is 28 days, but for many, it ranges from 21–35 days — and that’s completely normal! Only about 15% of women have a “textbook” 28-day cycle.
However, if your cycle lengths are consistently longer than 35 days or shorter than 21 days, it could point to an underlying problem. In that case, it’s worth talking to a doctor.
Ovulation: Your Cycle’s Main Event
Ovulation is when a mature egg is released from your ovary. This egg only survives for 12–36 hours, so knowing when it’s released is the key to identifying your most fertile days.
Many believe ovulation always happens on Day 14, but that’s only true if you have a 28-day cycle. In reality, ovulation typically happens about 12–14 days before your next period — which can vary from person to person.
How to Predict Your Fertile Window
If your cycles aren’t identical every month (and for most people, they aren’t), here’s a simple way to estimate your fertile days using your cycle history:
- Look at your last six cycles.
- Note your shortest and longest cycle lengths.
- Subtract 18 from your shortest cycle length.
- Subtract 11 from your longest cycle length.
The days between these two numbers are your fertile window.
Example:
- Shortest cycle = 25 days → 25 – 18 = Day 7
- Longest cycle = 30 days → 30 – 11 = Day 19
- Fertile window = Day 7 to Day 19
You can also spot ovulation by watching for changes in your body — like shifts in cervical mucus or basal body temperature.
How Periods Happen
If the egg released during ovulation isn’t fertilized, hormone levels drop and your womb sheds the lining it built for a potential pregnancy. This shedding is your period.
About 14 days after ovulation, if no pregnancy has occurred, menstruation begins — and the cycle starts over again, repeating its rhythm until menopause.
Why This Matters
The TTC journey can be tough and overwhelming, understanding your menstrual cycle is empowering. It can give you control, clarity, and confidence you need as you navigate your journey❤️