Every woman’s period is different. Some women bleed for , while others may bleed for a full week. Your flow might be light and barely noticeable, or heavy enough to make you uncomfortable. You may or may not get cramps, and if you do, they could be mild or intensely painful.

As long as your periods stay consistent, there’s probably no reason to worry about them. But you should stay alert in case you experience any changes to your monthly menstrual cycle.

Here are seven symptoms that are worth reporting to your doctor.

1. Skipped periods

have more regular periods than others, but get a period about once every 28 days. If your periods suddenly stop, there could be a few reasons for it. One possibility is pregnancy, and a pregnancy test can quickly and easily determine the answer to that.

If pregnancy isn’t the case, something else may be the cause of your skipped period, such as:

  • Intense exercise or significant weight loss. Overexercising can affect levels of hormones that control your menstrual cycle. When you lose too much body fat through diet or exercise, your periods can stop altogether. You need some body fat to manufacture hormones.
  • Weight gain. Gaining a lot of weight also can throw off your hormone balance and disrupt your menstrual cycle.
  • Continuous birth control pills. Certain birth control pills that provide a continuous dose of hormones means you’ll get fewer periods, and in some cases, they can stop your periods altogether.
  • Polycystic ovary syndrome (PCOS). With this condition, a hormone imbalance leads to irregular periods and the growth of cysts in the ovaries.
  • Extreme stress. Being under stress can throw off even the most regular menstrual cycle.
  • Perimenopause. If you’re in your late 40s or early 50s, you might be in perimenopause. This is the period of time leading up to menopause when estrogen levels decline. You’re officially in menopause once your periods have stopped for , but your periods can fluctuate a lot in the years leading up to menopause.

2. Heavy bleeding

Period blood volume varies from woman to woman. Generally, if you soak through one or more pads or tampons an hour, you have menorrhagia — an abnormally heavy menstrual flow. Along with the heavy bleeding, you might have signs of anemia, such as fatigue or shortness of breath.

A heavy menstrual flow is common. About of women will eventually see their doctor about it.

Causes of heavy menstrual bleeding include:

  • A hormone imbalance. Conditions like PCOS and an underactive thyroid gland (hypothyroidism) can affect your hormone production. Hormonal changes can make your uterine lining thicken more than usual, leading to heavier periods.
  • Fibroids or polyps. These noncancerous growths in the uterus can cause bleeding that’s heavier than normal.
  • Endometriosis. This condition is caused by tissue that normally lines your uterus growing in other parts of your pelvis. In your uterus, that tissue swells up each month and then is shed during your period. When it’s in other organs — like your ovaries or fallopian tubes — the tissue has nowhere to go.
  • Adenomyosis. Similar to endometriosis, adenomyosis is a condition that happens when tissue that normally lines the uterus grows into the uterine wall. Here, it has nowhere to go, so it builds up and causes pain.
  • Intrauterine device (IUD). This birth control method can cause heavy bleeding as a side effect, especially during the first year after you start using it.
  • Bleeding disorders. Inherited conditions like Von Willebrand disease affect blood clotting. These disorders can also cause abnormally heavy menstrual bleeding.
  • Pregnancy complications. An unusually heavy flow could be a sign of a miscarriage or ectopic pregnancy. It can happen so early that you may not realize you were pregnant.
  • Cancer. Uterine or cervical cancer can cause heavy bleeding — but these cancers are often diagnosed after menopause.

3. Abnormally short or long periods

Normal periods can last anywhere from two to seven days. Short periods may be nothing to worry about, especially if they’re typical for you. Using hormonal birth control can also shorten your cycle. Going into menopause can disrupt your normal cycles as well. But if your periods suddenly get much shorter, check in with your doctor.

Some of the same factors that cause heavy bleeding can make your periods longer than usual. These include a hormone imbalance, fibroids, or polyps.

4. Intense cramps

Cramps are a normal part of periods. They’re caused by uterine contractions that push out your uterine lining. Cramps a day or two before your flow begins, and last for two to four days.

For some women, cramps are mild and not bothersome. Others have more severe cramps, called dysmenorrhea.

Other possible causes of painful cramps include:

  • fibroids
  • an IUD
  • endometriosis
  • adenomyosis
  • pelvic inflammatory disease (PID)
  • sexually transmitted diseases (STDs)
  • stress

5. Bleeding between periods

There are a few reasons why you might notice spotting or bleeding in between periods. Some causes — like a change in birth control — aren’t serious. Others require a trip to your doctor.

Causes of bleeding between periods include:

  • skipping or changing birth control pills
  • STDs like chlamydia or gonorrhea
  • PCOS
  • an injury to the vagina (such as during sex)
  • uterine polyps or fibroids
  • pregnancy
  • ectopic pregnancy or miscarriage
  • perimenopause
  • cervical, ovarian, or uterine cancer

6. Breast pain

Your breasts might feel a little tender during your periods. The cause of the discomfort is likely fluctuating hormone levels. Sometimes there is pain right up into your armpit where there is some breast tissue called the Tail of Spence.

But if your breasts hurt or the pain doesn’t coincide with your monthly cycle, get checked out. Although breast pain due to cancer, it can be a symptom of it in rare cares.

7. Diarrhea or vomiting

Some women normally get an upset stomach during menstruation. In one study, of women reported having abdominal pain, diarrhea, or both around the time of their period.

If these symptoms aren’t normal for you, they could indicate PID or another medical condition. Because excessive diarrhea or vomiting can cause dehydration, report this symptom to your doctor.