When a period is due, there are a few ways a person can tell. Many people experience a range of physical and emotional symptoms called premenstrual syndrome (PMS) as their hormone levels drop.

In this article, we discuss a few common signs and symptoms of periods and explain how they differ from those of early pregnancy.

We also cover when people might want to consider seeing a doctor about their period symptoms.

a woman lying in bed and holding her stomach because she has pain there and it could be one of the signs that a period is dueShare on Pinterest
A person may experience abdominal bloating a few days before a period starts.

Many people experience PMS, which causes a range of symptoms, a few days before their period starts.

According to research, PMS symptoms appear in 95% of females of reproductive age.

PMS occurs after ovulation, which is when an ovary releases an egg into a fallopian tube.

Estrogen and progesterone levels decrease significantly after ovulation, which may explain why people have PMS symptoms.

PMS can cause physical and emotional symptoms.

Physical symptoms of PMS may include:

  • abdominal bloating
  • abdominal cramping
  • tender or swollen breasts
  • back pain
  • changes in appetite
  • pimples or acne
  • sleeping more or less than usual
  • headaches
  • sensitivity to light or sound
  • discharge becoming clear and slippery

Emotional symptoms of PMS may include:

  • irritability
  • anxiety
  • fatigue
  • food cravings
  • difficulty concentrating
  • feelings of sadness or apathy
  • crying spells or angry outbursts
  • decreased libido

PMS symptoms usually resolve once the body’s estrogen and progesterone levels start rising, which typically occurs 4 days after a person’s period begins.

PMS does not affect everyone in the same way. Some people have their period with no PMS or only a few mild symptoms, whereas other people experience severe symptoms that interfere with their daily activities. Symptoms are severe in about 5% of females with PMS.

PMS symptoms can change throughout a person’s life. People may notice different PMS symptoms as they get older or after their first pregnancy.

Periods and PMS can cause symptoms similar to those of early pregnancy.

Menstruation and pregnancy both affect a person’s hormone levels, which may lead to noticeable physical and emotional symptoms.

Bleeding or spotting

On average, menstrual bleeding occurs every 25–30 days. Most people lose about 2–3 tablespoons of menstrual blood during their period, but some individuals may have heavier or lighter periods.

Although bleeding does not typically occur during PMS, some people experience light bleeding or spotting.

This sign can also occur during early pregnancy. Nearly 15–25% of pregnant women report spotting or light bleeding during the first trimester.

When this occurs 1–2 weeks after a fertilized egg implants in the uterine lining, it is called implantation bleeding.

Implantation bleeding is much lighter than menstrual bleeding. It may look like a light pink or brown discharge, whereas menstrual blood appears bright red.

Women should contact their doctor if they experience heavy bleeding at any point in their pregnancy.

Abdominal pain or cramping

Both PMS and pregnancy can cause abdominal pain.

People may also notice mild-to-moderate cramping in the lower abdomen.

During pregnancy, these cramps feel similar to menstrual and premenstrual cramps, and they occur as the embryo grows and stretches the uterus.

Breast changes

Both PMS and pregnancy affect hormone levels, which may result in breast changes, such as:

  • pain
  • tenderness or sensitivity
  • swelling
  • heaviness

PMS-related breast changes usually resolve at the beginning or end of a person’s period.

However, breast changes that occur when a woman is pregnant persist throughout the pregnancy.


Fatigue is a symptom of both PMS and early pregnancy.

Fatigue during pregnancy might be due to elevated hormone levels during pregnancy.

An imbalance of a neurotransmitter called serotonin may contribute to feelings of fatigue during PMS. Serotonin helps regulate mood and the body’s sleep cycle, and its levels change throughout a person’s menstrual cycle. These changes may affect some people more than others.

People who feel extremely tired before their period may have a more severe type of PMS called premenstrual dysphoric disorder (PMDD).

The Office on Women’s Health estimate that nearly 5% of people who get periods have PMDD.

The symptoms that PMDD causes are similar to those of PMS but more intense.

These symptoms can include:

  • persistent irritability
  • symptoms of depression and anxiety
  • panic attacks
  • mood swings
  • difficulty falling asleep
  • severe daytime fatigue
  • food cravings
  • binge eating
  • headaches
  • bloating
  • cramps
  • joint and muscle pain

Changes in mood

The hormonal changes that occur during menstruation and pregnancy can affect a person’s mood, leaving them feeling anxious, sad, or irritable.

Mood swings are also common during both PMS and early pregnancy.

Persistent feelings of sadness, apathy, or irritability that last longer than 2 weeks may indicate depression or another mood disorder.

Many people experience a variety of physical and emotional symptoms before and during their period.

These symptoms usually resolve at the beginning or end of a period.

People may wish to see a doctor if they have symptoms that affect their daily life or occur outside of their period.

Many of the symptoms of PMS also occur during pregnancy.

These can include mood changes, fatigue, light bleeding or spotting, and abdominal pain.

People do not need to worry about these symptoms if they are mild and do not interfere with their daily activities.

However, heavy bleeding and severe abdominal cramping can indicate pregnancy complications, such as pregnancy loss and ectopic pregnancy.

Women should contact their doctor if they experience any of the following symptoms during pregnancy:

  • heavy bleeding
  • intense lower back pain
  • painful abdominal cramps
  • a sudden, intense headache
  • severe, persistent fatigue
  • difficulty breathing
  • vomiting several times a day

Many people experience physical and emotional changes before and during their period.

These changes include:

  • vaginal bleeding or spotting
  • abdominal pain or cramping
  • bloating
  • lower back pain
  • swollen or tender breasts
  • nausea
  • headaches
  • fatigue
  • acne
  • irritability
  • frequent mood changes
  • symptoms of anxiety or depression

Although these symptoms can cause discomfort, they should not interfere with a person’s daily life.

People may want to speak with a doctor if they continue experiencing emotional or physical symptoms that continue after their period ends.

Persistent feelings of sadness, hopelessness, or anxiety may indicate a mental health condition that doctors can treat with therapy and medication.

Heavy or persistent bleeding that occurs between periods may be a sign of an underlying health condition, such as ectopic pregnancy, an infection, or a hormonal imbalance.