Smartphone apps such as Clue, Glow, Eve, and Period Tracker are designed to help you monitor your menstrual cycle, ovulation, and other key points in your cycle. They can be an easy and data-driven means of monitoring your cycle length. [2] X Research source

If, for example, your cycle started on March 30 and your next period came on April 28, your cycle would be March 30 to April 27, and would total 29 days.

To find the average, add the total number of days of your cycle for each month that you have monitored. Then, divide that total by the number of months you monitored. This will give you your average cycle length. For example, you had a 28 day cycle in April, a 30 day cycle in May, a 26 day cycle in June, and a 27 day cycle in July, your average would be (28+30+26+27)/4, equalling a 27. 75 day average cycle.

If your doctor asks you the date of your last period, the answer is the first day of your last period, not the day it ended. [5] X Research source

If, for example, you have to change a super tampon every hour, you may have an irregularly heavy flow. Keep in mind that most women will have heavier days and lighter days. It is normal to have different levels of flow on different days. The severity of flow varies greatly from person to person. A heavier or lighter cycle isn’t inherently problematic. Instead, watch for very heavy cycles or completely skipped periods, which may be an indicator of another medical issue. [7] X Research source

If your symptoms are extreme enough that they make daily functioning difficult, contact your doctor. They may be able to help you find a solution or proper management program. If you notice symptoms suddenly happening that you have never experienced before, such as severe lethargy, you may also want to contact your doctor. In some cases, these could be an indicator of a larger medical issue.

You should also contact a medical professional if you experience severe cramping, migraines, lethargy, or depression in the days leading up to and during your cycle. Your doctor will be able to talk to you about your symptoms and run tests as necessary to see if changes in your cycle may be related to medical issues such as endometriosis, polycystic ovarian syndrome, thyroid disorders, or ovarian failure, among others.

So if you have a 28 day average cycle, your midpoint would be at 14 days. If you have a 32 day average cycle, your midpoint would be at 16 days.

Your egg can be fertilized up to 24 hours after it is released, and sperm can live in the fallopian tube for up to 5 days after sex. Having sex 5 days prior to ovulation, as well as on the day of ovulation, helps give your egg the best chance of fertilization.

Ovulation predictor kits are available from most pharmacies and drug stores, as well as online retailers.