You may experience spotting between periods and wonder what's going on. Here's a list of 10 possible reasons to help you stay informed.
What does spotting before your period look like vs. bleeding?
But first, what is spotting? Spotting is any light bleeding from the vagina that happens outside of your usual period. The amount and frequency of spotting can vary from person to person.
However, in general, there are some signs to look out for to know when it's considered spotting:
On average, a woman bleeds about 5-80 mL during her period. This bleeding is usually bright to dark red and can turn brown at the beginning or end of her period.
On the other hand, spotting is typically light pink or brown and is only about a teaspoon or so. In other words, rather than a whole pad or tampon being saturated like a period, you may only see a few spots of blood on your underwear. It usually fills no more than 1 pad per day.
If you are saturating through more than a pad per day, that's when it's considered bleeding.
Does spotting before your period mean you're pregnant?
In some cases, yes, but if you're using birth control to prevent pregnancy, there's probably another reason you're spotting. When taken perfectly the birth control pill has a less than 1% failure rate. Here's a list of a few of the most common reasons for spotting between periods, beginning with the most common causes:
1. Birth control and spotting
If you recently started birth control, it's common to have some spotting between periods while your body adjusts to the new hormones. Spotting, or breakthrough bleeding, can happen with birth control pills (oral contraceptives).
Spotting may also happen with other birth control methods like the ring, patch, injection, implant, and both the hormone-based and non-hormone-based intrauterine devices (IUDs).
Spotting can also happen if you:
Missed any combined or progestin-only contraceptive pills
Recently took emergency contraception
Have a problem with your ring, patch, or IUD
Ovulation is when the egg is released from the ovary and into the fallopian tube. Spotting during ovulation occurs in about 4.8% of women, and research has shown it may be due to hormonal changes (e.g., higher estrogen levels) around the time of ovulation. In one study (cited above), higher sex hormone levels around the time of ovulation were observed in women who reported midcycle spotting.
In addition to hormone fluctuations, ovulation spotting can occur because of endocrine abnormalities such as thyroid problems.
Bleeding or spotting outside of your expected period is sometimes a sign of early pregnancy. This is often referred to as implantation bleeding. Implantation bleeding occurs when the fertilized egg attaches to the interior lining of the uterus, about 6-12 days after fertilization occurs.
Sometimes it's hard to tell the difference between implantation bleeding and a normal menstrual period. However, here are some differences between the two:
Flow: Light spotting with no clots
Timing: 9 days after ovulation
Duration: 1-2 days
Color: Light pink or brown
Flow: Bleeding that fills a tampon or pad, sometimes with the presence of clots
Timing: 14 days after ovulation
Duration: 4-7 days
Color: Red or brown
4. Uterine fibroids
Uterine fibroids are noncancerous growths on the uterus. Fibroids can sometimes cause spotting between periods, heavy bleeding, or irregularities in your menstrual cycle.
Many women who have uterine fibroids don't have any symptoms. Yet some women experience spotting or heavy periods because of them. This is because uterine fibroids can grow on the inner lining of the uterus, where your period begins Some other signs of uterine fibroids include urinary problems, pelvic pain, including pain during sex, and lower back pain.
Another type of growth worth mentioning is polyps, which attach to the uterus. Polyps are usually benign growths. One study finds that less than 1% of polyps are cancerous, but they can cause bleeding between periods.
Endometriosis is an often painful condition that happens when extra tissue, similar to the lining of the uterus (endometrium), grows where it's not supposed to grow—in areas outside the uterus such as the pelvis, ovaries, or fallopian tubes.
The extra tissue from endometriosis acts like the normal lining of the uterus—it will thicken and shed with each menstrual period. However, bleeding in between periods can also happen during the month.
Bleeding from endometriosis usually causes pain that's more severe than that of a typical menstrual period. You may also have pain with intercourse, bowel movements, or urination.
6. Sexually transmitted infections
Certain sexually transmitted infections (STIs), such as chlamydia, can cause spotting between periods. Symptoms of an STI can occur between 1-3 weeks after exposure and may also include lower abdominal pain, painful urination, or foul-smelling vaginal discharge.
Some STDs like chlamydia and gonorrhea can cause a further complication called pelvic inflammatory disease, or PID. This condition can cause bleeding between periods.
Note: Remember, STIs can still be spread even on hormonal birth control, so always have protection with a condom to prevent the spread of STIs.
If you suspect you may have an STI, be sure to get STI testing and tell your partner so they can get tested too. Many public health departments and clinics have free STI testing.
7. Polycystic ovarian syndrome
Polycystic ovarian syndrome (PCOS) occurs in up to 10% of women and is the most common hormonal abnormality in reproductive-age women. This condition is often hereditary and causes symptoms such as weight gain, body or facial hair (hirsutism), acne, and hair loss.
Irregular bleeding or spotting from PCOS usually happens when women don't ovulate and the uterine lining gets thick from too much estrogen. Some women may have irregular periods that vary in length or won't have a period for a few months or more.
8. Vaginal dryness or infection
Vaginal dryness can sometimes cause spotting because the vaginal tissue is more delicate when dry. This can occur for several reasons including:
Menopause - During menopause estrogen levels drop and can result in vaginal dryness.
Medications: Vaginal dryness can be caused by medications. Some anti-depressants, allergy medications, and breast cancer treatments can have the side effect of vaginal dryness.
Breastfeeding: While nursing it can be normal for hormone levels to lower. This can cause a temporary vaginal dryness.
Vaginal infection can also cause bleeding between periods. This kind of infection can be caused by bacteria or yeast. There are typically other symptoms such as odor or vaginal discomfort.
Pelvic infections of the cervix, uterus or fallopian tubes can sometimes cause bleeding between periods. This is often accompanied by pelvic pain and bad-smelling vaginal discharge.
9. Cervical cancer
Though this condition is rare, cervical cancer may also cause abnormal bleeding. The cervix is the lower part of the uterus that opens into the vagina.
Bleeding from cervical cancer can also occur after sex or menopause and may make menstrual periods longer and heavier than usual. Other signs of cervical cancer include vaginal discharge that's mixed with blood, pain during sex, or pain in the pelvic region.
Because cervical cancer is rare, your healthcare provider would rule out other causes of these symptoms first. Often, symptoms of cervical cancer can mimic other conditions such as pelvic inflammatory disease or STIs.
10. Thyroid disease
The thyroid is a small gland located at the base of the neck that's responsible for controlling your body's metabolism such as how fast you burn calories. Women have higher rates of thyroid disease than men.
Having an overactive or underactive thyroid can cause abnormal bleeding because your thyroid helps control your menstrual cycle. Thyroid disease can cause periods to be light, heavy, irregular, or absent depending on whether there is too much or too little thyroid hormone in the body.
How many days of spotting before your period is normal?
For women who are getting their period for the first time, it's common to have some spotting and irregular cycles for the first year or so as your hormones regulate and you start having regular periods.
You should also be on alert for other changes around your first period, such as breast development and pubic hair growth. In addition, any bleeding that occurs before these signs of puberty should be alerted to your healthcare provider.
Irregular bleeding is defined as cycles that vary in length by more than 7-9 days. Therefore, if you see spotting 2-3 days before your period starts, it's likely that your period has just come a bit early or is going to start in the next few days.
When to ask a healthcare provider
Any spotting or bleeding outside of your usual period is cause for notifying your healthcare provider, but some situations warrant more immediate attention than others. For example, if you have any signs of pregnancy, such as spotting accompanied by nausea, vomiting, or breast tenderness, take a urine pregnancy test. Call your provider with the results and your symptoms.
Having severe pain in your lower abdomen (pelvic and/or abdominal pain)
Soaking through a pad or super tampon in two hours or less and quickly saturating another
Blood clots in your vaginal bleeding
When in doubt, bring your symptoms to a healthcare provider. That way, your healthcare provider can help you rule out possible causes and figure out the root cause of spotting.
Davis E, Sparzak PB. Abnormal uterine bleeding. StatPearls. Published January 2021.
American Academy of Family Physicians. Familydoctor.org. Bleeding During Pregnancy - What's Normal? Reviewed June 3, 2019.
National Health Service. Nhs.uk. What causes bleeding between periods? Reviewed November 5, 2019.
Dasharathy SS, Mumford SL, Pollack AZ, Perkins NJ, Mattison DR, Wactawski-Wende J, Schisterman EF. Menstrual bleeding patterns among regularly menstruating women. Published March 15, 2012.
American Pregnancy. Americanpregnancy.org. What is Implantation Bleeding? Accessed September 6, 2021.
University of Michigan Health. UMwomenshealth.org. Uterine Fibroids & Abnormal Bleeding. Accessed September 6, 2021.
Mayo Clinic. Mayoclinic.org. Endometriosis. Published July 24, 2018.
Mayo Clinic. Mayoclinic.org. Sexually transmitted diseases (STD) symptoms. Published April 30, 2020.
UCLA Health. Uclahealth.org. Polycystic Ovarian Syndrome (PCOS). Accessed September 6, 2021.
University of Michigan Health. UMwomenshealth.org. Abnormal Vaginal Bleeding. Reviewed February 26, 2020.
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University of Michigan Health. UMwomenshealth.org. [Symptoms of Pelvic Infection. Reviewed July 17, 2020.
American Cancer Society. Cancer.gov. [Signs and Symptoms of Cervical Cancer. Reviewed January 3, 2020.
Office on Women's Health. Womenshealth.gov. Thyroid Disease. Reviewed April 1, 2019.