Hormonal and other changes that occur in the latter half of the menstrual cycle often trigger physical and emotional symptoms that signal your period is coming.

Roughly 80 percent of women experience at least one premenstrual symptom in the days leading up to their period, according to an August 2016 American Family Physician article. These physical and/or emotional symptoms are thought to occur primarily due to changes in the levels of the female hormones estrogen and progesterone as your period approaches.

Depending on the usual length of your cycle, you can experience premenstrual symptoms from 1 to 2 weeks before your period starts — although symptoms usually peak a day or two before bleeding commences. Premenstrual symptoms occur during the second half of your cycle after you ovulate.

Physical Symptoms

Physical symptoms that signal your period is coming soon vary from one woman to another and sometimes from one cycle to the next. Menstrual cramps typically signal your period will begin within 24 to 48 hours. Some of the many possible additional physical symptoms you might experience in the days leading up to your period include:

Emotional and Mental Symptoms

• Irritability 
  
• Moodiness
• Short temper
• Impulsiveness
• Crying easily
• Sadness
• Decreased sociability
• Decreased interest in sex
• Reduced ability to concentrate
• Forgetfulness
• Sleepiness
• Reduced motivation :

Predicting Your Periods

Tracking your menstrual cycles and premenstrual symptoms can help you more accurately predict your periods — and avoid a potentially embarrassing surprise. A large number of apps are available for both Apple and Android smartphones, many of which allow you to track premenstrual symptoms. However, some period tracking apps are inaccurate.

A study published in June 2016 in Obstetrics and Gynecology found that only 20 out of 108 free period tracking apps evaluated were accurate. Talk with your healthcare provider about recommendations regarding the best apps available to track and predict your periods. Alternatively, you can always go old school and track your symptoms in a diary or on a calendar.

Normal Symptoms Versus Premenstrual Disorder

For most women, premenstrual symptoms are uncomfortable but do not significantly interfere with daily life. If you frequently experience premenstrual symptoms that interfere with your work, academic or home life, talk with your healthcare provider as you might have a premenstrual disorder or a medical condition that mimics a premenstrual disorder.

According to the previously mentioned August 2016 American Family Physician article, premenstrual disorders affect an estimated 12 percent of women of childbearing age. Premenstrual syndrome is less disabling than the more severe premenstrual dysphoric disorder, which affects an estimated 1 to 5 percent of menstruating women 25.