How do you calculate ovulation when your menstrual cycles are irregular? Check out these 4 ways to predict ovulation with fair accuracy even with irregular periods.

Whether you’re trying to conceive or want to avoid unplanned pregnancy, you need to know when you ovulate.
The mid-cycle ovulation estimate can be vague and inaccurate, however, especially when your menstrual cycles are irregular.
4 Ways to Calculate Ovulation When Your Periods are Irregular
So here are 4 ways you can calculate your ovulation with a fair accuracy:
1. Monitor Your Vaginal Discharge
As you approach ovulation, your estrogen level increases. This triggers the release of fertile mucus to facilitate a possible encounter of the sperm and the egg.
The process usually begins 6 days before ovulation. During this time, you may notice an increasing amount of moist and creamy discharge.
When the discharge becomes clear and stretchy (egg white-like), you can be sure that you’re ovulating.
Typically, 48 hours before and after the appearance of the egg white-like discharge are considered your ovulation days.
Monitoring your vaginal discharge is a fairly accurate way to calculate your ovulation. It’s simple, and it allows you to pinpoint your fertile days as well as the actual ovulation days.
To learn more about the various types of vaginal discharge and what they mean, read What Does Your Vaginal Discharge Tell You.
2. Track Your Basal Body Temperature
Basal body temperature (BBT) is your body’s temperature at rest, without any additional activities such as eating, working, moving, etc. Hence, it’s best measured the first thing in the morning before you get out of bed.
After ovulation, BBT typically rises by 0.4 degrees Fahrenheit or 0.2 degrees Celsius.
Ovulation usually occurs on the last day before the rise of BBT.
The advantage of tracking your BBT is that it plots your estrogen and progesterone activities visually. And it can reveal a specific pattern of hormonal imbalance for a trained pair of eyes.
The disadvantage is that by the time you notice a rise of BBT, ovulation has already occurred.
Therefore it’s not the best method to predict ovulation, but rather to confirm it.
It also takes more work than other methods. And it’s less accurate if you have an irregular lifestyle (e.g., travelling, staying up at night, etc.)
3. Calculate Based on Your Menstrual Cycles
If you have a regular cycle, ovulation is likely to occur 14 days before your next expected period.
Since you won’t be able to pin down the exact day when you ovulate from this method, you need to add 5 days before and 4 days after this date to get a date range.
Generally speaking, from day 9 to day 18, you’re fertile and likely to get pregnant.
How about if your cycles are irregular? This is how you can calculate your ovulation:
- First day of ovulation = the shortest cycle length – 18 days
- Last day of ovulation = the longest cycle length – 11 days
For example, if your shortest cycle lasts for 25 days and the longest lasts for 35 days. Your ovulation window could be from day 7 (25 minus 18) to day 24 (35 minus 11).
As you can see, the date range can be pretty wide if your cycles are very irregular. This, therefore, is a less accurate method to calculate ovulation when compared to the other methods.
4. Use an Ovulation Strip
What triggers ovulation is a surge of luteinizing hormone (LH) released by the pituitary gland. This LH surge happens 24-48 hours before ovulation.
An ovulation strip can detect the higher level of LH in your body, hence indicating ovulation. This method is a very accurate and convenient option, if you don’t mind spending some money.
Hope you find these methods helpful in calculating your ovulation/fertile days. Please feel free to ask a question and share your experience with us.
P.S. When you have irregular periods, you want to do all you can to restore its natural rhythms. For this, consider taking Chasteberry (Vitex), the best natural remedy to regulate menstrual cycles.
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