You may experience spotting between periods and wonder what's going on. It's important to remember: spotting before your period is normal, and can often be explained by a number of common causes. Below, find a list of 10 possible reasons to help you stay informed, or jump straight to the section most relevant to you:
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.
What does spotting before your period look like vs. bleeding?
While spotting has many causes and can look different depending on the person, there are a few common signs to look out for to know when it's considered spotting vs. menstrual bleeding.
Spotting Before Your Period
On average, people who menstruate bleed about 5-80 mL during their period. This bleeding is usually bright to dark red and can turn brown at the beginning or end of their 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.
Back to basics: What is a period? When not taking birth control, a period, or menstruation, is bleeding from the vagina that happens cyclically. Approximately every month the ovaries release an egg. This starts a hormonal cycle that results in a period if conception does not occur. But if no pregnancy happens, the uterus sheds its lining every month. Menses, or the contents of your period is more than just blood, it also contains tissue from the lining of the uterus.
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.
What else causes spotting between periods?
Here's a list of a few of the most common reasons for spotting between periods, beginning with the most common causes including:
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 and irregular bleeding can also happen if you:
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 people who menstruate, 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 and people who menstruate 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:
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 and people who menstruate who have uterine fibroids don't have any symptoms. Yet some people 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.
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 people who menstruate, and is the most common hormonal abnormality in reproductive-age people. 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 people don't ovulate and the uterine lining gets thick from too much estrogen. Some women and people who menstruate 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:
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
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 and people who menstruate 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 people 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 hormone levels 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 abnormal 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.
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.