Is Period Bleeding a Mirror of the Lining of Your Uterus?

menstrual bleeding and the lining of the uterus

June 22, 2020 | By: Monica Rincon, MSc., NFP Health Professional 

A period cycle, or menstrual cycle, occurs monthly (every 21-35 days) in women during their reproductive life. This process is due to the ovarian hormones that fluctuate before and after ovulation, such as estrogen and progesterone. Tracking and understanding your cycle can give you useful information about your fertility health and your chance of pregnancy.

What is Actually Happening During Your Menstrual Cycle?

First, an immature egg produces estrogen by the stimulus of the Follicle-Stimulating Hormone (FSH). Estrogen acts by invigorating the cervix to produce mucus and by building up the lining of the uterus. Once ovulation has occurred, progesterone from the ovary keeps the lining of the uterus steady from 9 to 18 days. Therefore, the amount of bleeding during menstruation is a reflection of what had happened hormonally during the cycle.

What Does Normal Menstrual Flow Look Like?

Every woman has a unique pattern of menstruation, but what is healthy for a woman trying to get and sustain a pregnancy? A normal length of menstrual bleeding is between three to seven days. At least, a day of heavy or moderate bleeding is optimal. 

A normal menstrual flow results in about 30-60 mL of blood loss (2-4 Tablespoons or one regular tampon every two hours). If you notice excessive and heavy bleeding where you are losing 80 or more milliliters during your period (menorrhagia), you should consult your doctor. It could be a sign of an endocrine disorder or intrauterine abnormality.

Light bleeding without the presence of medium to heavy flow is not considered a regular menstrual period and  could be due to contraceptive use or some endocrinological issues that must be investigated. 


Tracking Your Flow

Use the following as a guideline to determine your menstrual flow as Heavy (H), Moderate (M), Light (L), Spotting (S) (light red) and Brown (B)

Period flow and spotting illustration

Menstrual Flow vs. Spotting

It is important to differentiate other types of bleeding different from menstruation such as red light spotting after your LH peak is detected. It could mean “high fertility” as a healthy sign, or it could be an abnormal sign such as another hormonal gland that is not working properly. When tracking your menstrual flow, do not include spotting.  Begin with the first day of regular flow. 


Try free Premom ovulation tracker app to track your cycle


Menstruation and Healthy Hormonal Levels


If a woman produced more estrogen than expected, her menstrual bleeding could be a little heavier, but still in the normal range. 

How can you get a sense of the levels of your estrogen production during a menstrual cycle? How does it reflect an optimal lining? You can test your estrogen in urine by using some fertility monitors or by charting your cervical mucus during the ovulatory phase of the cycle.


Optimal levels of progesterone are only enough if the lining of the uterus can be sustained between 9 to 18 days after ovulation. You can monitor your levels of progesterone by tracking the length of your luteal phase between ovulation and the start of your next menstrual cycle. Find this easily under “Report” in the calendar of your Premom app.


The important message of menstrual bleeding is to reflect that the ovarian hormones are doing their job and their levels are balanced and synchronized in every menstrual cycle. Even though a vaginal ultrasound can determine the thickness of the lining of the uterus, this is not a routine exam. Charting your blood flow during menstruation is a powerful indicator of your reproductive health, especially if a woman wants her uterus to nest her pregnancy.


Try Premom free ovulation tracker app to track your cycle


About author  

Monica Rincon is a certified Marquette Method Natural Family Planning (NFP) Teacher / fertility awareness educator and a medical microbiologist. Schedule a consultation with Monica right through your Premom app! 


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Updated August 24, 2020


estrogen, fertility, infertility, menstrual cycle, period, period app, progesterone
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