Irregular Periods: What is normal, and what is not

Aug 10, 2022 | By Patrice Winchester, RN, BSN

As women, what is considered a “normal” cycle will vary from person to person. So with these variations in cycles being common, how in the world do we know what is considered “normal” and what is considered “irregular?”

Irregular Periods: What is normal, and what is not

What does a normal period look like?

In short, there are 4 phases making up a normal woman's period, menstruation phase, follicular phase, ovulation phase, and luteal phase, with the average total length between 21 to 35 days.

Before we can define what is considered an irregular cycle, we must first understand the basis of a normal cycle. Physical and hormonal changes would occur within the female body to prepare the female for conception and a healthy pregnancy. 

Some of the physiological changes that occur during the entirety of the cycle include the maturation of the egg, release of the egg, fertilization and implantation of the egg, or the shedding of the uterine lining (aka your period). Hormonal changes occur depending on the particular phase of the cycle and originate from the pituitary gland and the ovaries themselves. That means your brain and ovaries are constantly in communication! 

So let’s break down the different phases of your cycle: The first phase of the cycle is the menses phase and it is what we all refer to as our period or “Aunt Flow”

The second portion of the menstrual cycle is the follicular phase. This phase can vary slightly from month to month and typically last from day 6 to 14. During this time estrogen rises which causes the lining of the uterus to thicken. Also rising during this time is a hormone called FSH (follicle stimulating hormone) which causes the follicles on your ovaries to grow, helping to mature one egg for ovulation. 

The third phase is the ovulatory phase aka the main event! This phase occurs roughly around cycle day 14-17 of the cycle, but can and will vary month to month and woman to woman. A sudden increase in the LH hormone (luteinizing hormone) causes the ovary to release the egg. That rise in LH is what you’re tracking with ovulation tests and the Premom app to find your most fertile days if you’re looking to achieve pregnancy. 

The final phase of the glorious menstrual cycle is the luteal phase. This phase is typically about the same length month to month in a normal cycle. This is the time that the ovulated egg will travel down the fallopian tube and into the uterus. The hormone progesterone now starts to rise to help prepare the uterine lining for a healthy implantation and pregnancy.

If fertilization of the egg occurs, ideally the fertilized egg will then attach itself to the uterine wall, and if no conception occurs, progesterone levels begin to fall and the lining of the uterus then sheds, starting the cycle all over at phase one again.

Menstrual bleeding during a normal cycle can vary from 2 to 7 days. Normal does not mean that you have the exact same number of bleeding days or days within a cycle, but relatively speaking, your periods are mostly predictable and similar in nature. A few days difference from month to month does not indicate that you have an irregular cycle.

What is considered an irregular period?

According to ACOG (American College of Obstetrics and Gynecology), an irregular period can be defined as a cycle occurring more frequently than every 21 days, or less frequently than every 35 days. It can also mean that the length of your bleeding varies greatly. 

Some other irregularities to be aware of that are not “text book” would include things like:

  • Not bleeding at all or very little bleeding
  • Spotting in between periods
  • Very heavy bleeding
  • Long bleeding periods
  • Severe cramping

It is common for most women to experience a few “irregular” periods in their lifetime and there are many different factors that can cause someone with a relatively normal cycle to have a random irregular period. 

Lifestyle factors that may cause the irregularity might include:

  • Sudden increase in stress level
  • Sudden decrease in weight
  • Strenuous physical activity
  • Some types of medications. 

It is wise to track your cycles for at least 6 months to get an idea of how regular or irregular they tend to be before assuming you have irregular periods.

What causes irregular cycles?

Let’s assume you have been tracking your periods for months, or maybe even years, and you definitely have experienced the irregularities mentioned above. What now? What does that mean? Why is this happening to you? 

Well, there are a variety of reasons that you may be experiencing irregular cycles including:

  • Eating disorders or being underweight or overweight
  • Continuous strenuous activity
  • PCOS
  • Prolonged birth control use
  • Hormonal IUD’s
  • Certain fertility drugs
  • Uterine fibroids
  • Endometriosis
  • Uterine polyps
  • Pelvic inflammatory disease
  • Pregnancy
  • Breastfeeding
  • Physiological abnormalities of the female reproductive tract
  • Thyroid disorders
  • Uterine or cervical cancer
  • Premature ovarian failure

*Please note that this list is not all inclusive.


Try a free Premom app to know more about your period


Still unsure about if your cycles are regular? Start cycle tracking! 

First step to figuring out if you are experiencing normal or irregular cycles is to get very familiar with your cycle. Tracking your cycle in detail is very important in monitoring of irregularities that may be considered normal and what may be of concern.

Using the Premom app is a very helpful tool in keeping track of all of your cycle details.

Here are questions to ask yourself to examine your cycles:

  • Do you notice an LH peak or is it missing?
  • Do you see a BBT spike after your LH peak?
  • Do you notice eggwhite cervical mucus near your LH peak?
  • How long does your period typically last?
  • Is it longer or shorter month to month?
  • How heavy is your flow? 
  • Does it vary greatly month to month? 
  • Do you bleed extremely heavy (soaking through a super plus tampon or pad every hour for consecutive hours)? 
  • Do you have clots?
  • How painful are your periods?
  • Do you bleed/spot in between periods?
  • Do you have any mood or behavior changes before, during, or after your period?
  • If tracking ovulation, do you tend to ovulate around the same cycle day each
  • Month?
  • How many days in between periods are there? 
  • Does it vary by a few days or is it changing?

This list of varying causes seems daunting when facing the fact that you are experiencing irregular cycles. If you are experiencing irregular cycles or any other symptoms that you feel are not considered “normal”, it is important to document your symptoms and speak to your OB/GYN for further testing.

There are many modifiable lifestyle changes that can help to regulate your cycle, and some are an easier fix than others. On the flip side, there are some medical diagnoses that need intervention from your provider to help regulate your period and to ensure all factors that may affect your fertility are addressed.


Try a free Premom app to know more about your period



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