How Common Is It for a Menstrual Cycle to Be Late?

Menstrual cycles can change from one month to the next. A cycle is considered normal when it happens every 21 to 35 days, but small changes of a few days are common. Studies show that many women have irregular or slightly delayed periods from time to time. This can happen for many reasons including changes in stress, diet, or exercise. Young women and those who have recently started their periods often see more variation as their bodies adjust to hormone changes. Women experiencing perimenopause (the gradual decrease of hormone production by the ovaries) commonly experience irregular periods even if they had previously experienced regular periods. Having a cycle that is occasionally late is not unusual, but if you experience irregular periods frequently or have concerns, it is a good idea to talk with a healthcare provider for further guidance.