Spotting Before Your Period? Here’s Why It Could Be Happening

Content medically reviewed by Amanda Tran, MD

Seeing blood when you go to the bathroom and you're not having your period can be alarming. But light bleeding, or spotting, between periods can have many causes and is usually nothing to worry about.

"Spotting usually appears as a brownish or pinkish discharge," said Dr. Amanda Tran, OB/GYN at Essentia Health. "In many cases, it is light and lasts only a day or two. However, sometimes heavier breakthrough bleeding can be a sign of a problem. It's important to understand when you may need to see a health care provider."

According to a recent study, more than 40% of women experienced at least one day of spotting before their period. But what causes this to happen, and when should you be concerned?

Why You Might Be Spotting Before Your Period

Any bleeding that occurs outside of your regular period is considered abnormal vaginal bleeding. For many women, bleeding between periods happens due to hormonal changes related to your menstrual cycle or hormonal birth control.

When you ovulate, your ovaries release an egg, which travels to the uterus via a fallopian tube. Some women experience spotting during ovulation, as well as a dull pain in the lower abdomen. This is normal and not cause for concern.

Other reasons include your birth control method and certain health conditions.

Birth Control Methods That Cause Spotting

Certain birth control methods can also cause spotting. While this can happen with any form of hormonal birth control, it's more common with –

• Birth control implants, small plastic rods placed just under the skin of the upper arm. If you experience spotting after the first few months, it’s likely to continue in the same pattern. Spotting will sometimes improve after the first six months, but it’s important to discuss any concerns with your provider.
• Hormonal intrauterine devices (IUDs), small plastic devices inserted into the uterus, where they release hormones. Spotting is common in the first few months after placement.
• Low-dose or ultra-low-dose birth control pills, which contain lower levels of hormones than some others that are available. Taking the pill continuously so you don’t get a regular period increases the chances of light spotting.

If you smoke or don't take birth control pills consistently, the chances of spotting increase.

If abnormal bleeding is a side effect of your birth control method, your provider can help determine the best way to avoid bleeding. This may mean changing your dosage or switching to a different method.

Health Conditions That May Cause Abnormal Vaginal Bleeding

In addition to hormones, certain conditions can cause spotting or heavy bleeding between periods. These include –

• Adenomyosis. This is a condition in which the endometrium, the lining of the uterus, grows into the uterine wall. Common signs include heavy menstrual bleeding and pain.
• Cervical cancer. While early cervical cancer typically has no symptoms, symptoms can develop when cancer spreads to other tissues. This could cause spotting or bleeding between periods or after sex. Other symptoms could include longer or heavier periods or bleeding after menopause. 
• Endometrial cancer. When cancer forms in the lining of the uterus, abnormal bleeding can be an early sign. This could be bleeding between periods or spotting after menopause. Endometrial intraepithelial neoplasia (EIN), a precancerous lesion, also causes bleeding.
• Pelvic inflammatory disease (PID). PID is an infection in the reproductive organs, including the uterus, ovaries, cervix, and fallopian tubes. Untreated sexually transmitted infections may result in PID. Abnormal vaginal bleeding can be one of the symptoms.
• Polycystic ovary syndrome (PCOS). This condition occurs due to an imbalance of hormones that is due to inconsistent ovarian function. PCOS can lead to irregular periods and abnormal bleeding.
• Uterine fibroids or polyps. Fibroids are growths that form on the cervix, the broad ligament, and the uterus, and polyps can grow inside the cervix or the uterus. Both are noncancerous but can cause breakthrough bleeding or heavy periods.
• Vaginitis. Infection caused by overgrowth of yeast or bacteria in the vagina can cause irritation and bleeding. This is typically associated with vaginal discharge, itching, and odor.

Other factors like stress, weight loss, changes to your diet or exercise routine, and the use of blood-thinning medications can also sometimes cause abnormal bleeding.

When Should You See a Provider for Abnormal Bleeding?

“It’s a good idea to see your provider for any bleeding that concerns you,” Tran said. “If you are pregnant and experience heavy bleeding or bleeding along with pain, cramping, lightheadedness, or other symptoms, seek care immediately. If you are not pregnant and have unusual bleeding that requires changing pads or tampons every hour and have chest pain, shortness of breath, or feel dizzy, you also need immediate medical care.”

If other types of spotting or light bleeding occur between periods, keep track of symptoms—such as how many days you noticed breakthrough bleeding, how heavy it was, if there were large clots, and how many pads or tampons you used. Share this information with your provider, who can help determine the reasons for abnormal bleeding and whether additional testing and/or treatment is necessary. If you are trying to conceive and experience persistent premenstrual spotting, you should see your provider.

Your provider may perform tests, such as blood tests, a Pap test, or urinalysis, to pinpoint the cause. In some cases, you may also need imaging tests.