Is it possible to menstruate without ovulating?

Dear Alice,

Is it possible to menstruate (have a period) without ovulating?

Dear Reader, 

Here’s the lowdown on your flow: It’s not technically possible to menstruate without ovulating. However, it’s possible to have vaginal bleeding even if you haven’t ovulated. In some instances, it may even mimic your regular period. This can happen for many reasons, such as medical conditions, hormone changes, and infection. 

Before continuing, it may be helpful to learn more about the phases of the menstrual cycle. A new cycle begins with the periodic (usually monthly) shedding of the uterus lining. About two weeks before their period begins, a person will release an egg from the ovaries. This process is called ovulation. The egg then moves down the fallopian tubes, where it waits for sperm. In the next phase, some hormones signal the body to thicken the uterine walls, preparing a soft tissue bed for a fertilized egg. If sperm doesn’t fertilize the egg, the cushy lining of the uterus isn’t needed anymore. The uterine lining breaks down and sheds, marking the start of a new cycle. And then the cycle repeats! 

Ovulation is needed for Aunt Flo to come knocking. It can be tricky to tell when exactly you’re ovulating. However, some of the more common signs of ovulation include clear and slippery cervical mucus (similar in consistency to egg whites), a slight increase in body temperature, tender breasts, and bloating. Sometimes, however, ovulation might feel more like ovu-late-tion. Certain health conditions and life events may affect ovulation or cause it to stop completely. These include: 

  • Breastfeeding. The hormones that help to produce breast milk may stop the menstrual cycle. 
  • Menopause. As the body ages, this cycle naturally slows down and eventually stops menses. 
  • Polycystic ovary syndrome (PCOS). PCOS occurs when the ovaries over-produce certain hormones, leading to an imbalance of hormones in the body. It can cause unpredictable ovulation, irregular periods, and other symptoms
  • Primary ovarian insufficiency. This condition occurs when the ovaries stop working early (usually before the age of 40). This can lead to irregular ovulation. 
  • Amenorrhea. This is the medical term for missing periods. It may be caused by weight changes, excessive stress or fatigue, or extreme exercise routines. 

List adapted from Cleveland Clinic 

It’s possible to have vaginal bleeding even if you haven’t ovulated. This is called abnormal uterine bleeding and is a common condition. It affects around one-third of people who have a uterus and are of child-bearing age. There are several reasons for vaginal bleeding outside of a regular menstrual cycle or bleeding that isn’t caused by menstruation at all. Some of these include: 

  • Health or medical conditions such as uterine fibroids (non-cancerous growths in the muscle tissue of the uterus), hypothyroidism (underactive thyroid gland), and cancers of the cervix, endometrium, ovaries, and fallopian tubes. 
  • Medications such as blood thinners. 
  • Pregnancy complications such as ectopic pregnancy (when a fertilized egg grows outside the uterus), premature labor, and miscarriage. 
  • Hormonal imbalances due to stress, PCOS, or hormonal contraception. 
  • Menopause and hormonal transitions. 
  • Injury or trauma to the vagina due to the insertion of a foreign object, for instance. 
  • Infection of the pelvic cavity and urinary tract. Sexually transmitted infections (STIs) can also lead to vaginal bleeding. 

List adapted from Cleveland Clinic 

Additionally, hormonal birth control (such as pills, patches, and intrauterine devices) can affect ovulation and vaginal bleeding. These devices stop ovulation and thicken the cervical mucus. This makes it harder for sperm to swim to an egg. These methods are designed to have a one-week break in hormones, which may cause withdrawal bleeding. This is often shorter and lighter than a typical period. However, many still refer to it as their period. Further, some people have breakthrough bleeding, also known as spotting, which is bleeding between withdrawal bleedings or bleeding separate from your normal period. 

“Go with the flow” may be good advice, but not when it comes to your monthly flow. You may want to speak with a health care provider if you experience changes in your period or bleeding during pregnancy or after the start of a new medication. They may be able to evaluate your symptoms and run tests to find out what’s causing these changes. 

Looking for more on menstruation and ovulation? Consider checking out the Go Ask Alice! archives—there's lots more there for you to cycle through! 

Last updated Jan 26, 2024
Originally published Feb 27, 2004