How long is a menstrual cycle

Most women believe the average menstrual cycle is 28 days long, but cycles can range from 23 to 35 days. Read on to learn more about periods and fertility.
Do you know how long a menstrual cycle is? You may answer with the textbook 28 days, but a study of more than 30,000 women found that 87% had cycles that fell in the range of 23 to 35 days1.

Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles

Your menstrual cycle explained, Menstrual cycle phases

Is there a scientific explanation for the length (28 days on average) of the menstrual cycle? - Quora

Menstrual Cycle (Normal Menstruation): Overview & Phases

Understanding Menstrual Cycles, Your Periods and Ovulation - Clearblue

How Your Period and the Menstrual Cycle Works

Why is my Menstrual Cycle getting Shorter?

What's “normal”?: Menstrual cycle length and variation

/wp-content/uploads/202

The menstrual cycle: an overview

4 Ways to Calculate Your Cycle Length - wikiHow

The Menstrual Cycle - Phases, hormones and their functions

Menstrual Cycle - Women's Health Issues - Merck Manuals Consumer Version