You look at your underwear and notice some small brown spots. It’s not time for your period yet — what’s going on here?

It’s likely spotting, which refers to very light bleeding that happens outside of your usual menstrual cycle. It’s not enough to fill a pad or a tampon, but it’s often visible on toilet paper or underwear.

Spotting can range in color from light pink to dark brown. Brown spotting gets its color from old blood, which can start making its way out of your body one to two weeks before the start of your period.

For some, this is just a normal part of their cycle. For others, it may be a symptom of an underlying health condition.

Here’s a look at the potential causes of brown spotting and other symptoms to watch for.

Brown spotting is often just sign of ovulation or your actual period starting. This is totally normal and nothing to be concerned about.

Ovulation

If you have brown spotting that starts a good two weeks before your period, it could be a sign of ovulation-related hormonal changes.

Typically, you ovulate about 10 to 16 days after the first day of your last period. This is when your ovaries release an egg for fertilization.

Ovulation occurs when your estrogen levels are high. These drop after the egg is released. This decrease in estrogen can cause some bleeding and spotting.

But if you take birth control pills, your brown spotting may be a sign of something else. Typically, birth control pills prevent ovulation.

Your period

Sometimes, brown spotting is just a precursor to your period. The brown blood or discharge may be the remnants of old blood that was never fully shed from your uterus the last time you had your period.

This usually isn’t cause for concern. But if you’re regularly having very short cycles that last for only two weeks or so, it’s best to follow up with your healthcare provider.

If you use hormonal birth control, brown spotting may be a sign of breakthrough bleeding. This is bleeding that occurs between periods as your body adjusts to the hormones from your birth control.

You’ll likely experience some spotting and breakthrough bleeding in the first three to six months after starting a new method of hormonal birth control. It’s especially common if you’re taking a birth control pill that doesn’t have estrogen.

You can also have spotting on other estrogen-free birth control methods, including Depo-Provera shots or hormonal intrauterine devices, such as Mirena.

Brown spotting can also happen if you take birth control pills and miss a few doses. Once you get back on schedule with your pills, the spotting should go away.

When to consider a switch

It can take several months for your body to adjust to a new method of birth control.

But if you continue to have spotting or breakthrough bleeding for more for more than six months, talk to your healthcare provider about switching to a different method.

Healthline

Sometimes, brown spotting before your period is actually implantation bleeding. This is mild bleeding or spotting that happens when a fertilized egg implants itself in your uterus. Keep in mind that only some pregnant people experience implantation bleeding.

Implantation bleeding usually happens a week or two after ovulation and resembles brown spotting. The bleeding tends to only last for a day or two. In some cases, it might be accompanied by implantation cramping.

Other symptoms of early pregnancy include:

  • breast tenderness
  • fatigue
  • frequent urination
  • nausea
  • vomiting

Learn more about how long implantation bleeding lasts and when to consider taking a pregnancy test.

Perimenopause refers to the period of time leading up to menopause. During this time, which can start up to 10 years before menopause, your hormones start to fluctuate. In response, you might not ovulate or menstruate as often as you once did.

If you’re in perimenopause, irregular periods and spotting between periods are often normal. You might have a long, heavy period followed by a relatively light, short period.

But if you have very heavy bleeding or bleeding that occurs more often than every three weeks, follow up with your healthcare provider.

Sometimes, brown spotting between periods is a symptom of an underlying condition that needs treatment.

Sexually transmitted infections

Sexually transmitted infections (STIs) can cause irritation in your vaginal tissues that can lead to bleeding and spotting.

Additional symptoms you might experience related to an STI include:

  • pelvic pain
  • burning sensation when urinating
  • fever
  • nausea
  • pain during sex
  • unusual or foul-smelling discharge, such as green or yellow discharge

If you have symptoms of an STI, see a healthcare provider as soon as possible to avoid any complications or transferring the infection to others.

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) results from an infection in your reproductive system, including some sexually transmitted infections.

In addition to brown spotting, PID can also cause:

  • burning sensation when urinating
  • pain during sex
  • pelvic pain
  • unusual or foul-smelling discharge
  • fevers or chills

It’s important to follow up with your healthcare provider if you have symptoms of PID. Left untreated, it can have lasting effects on your reproductive health, including fertility. In many cases, the condition resolves with a course of antibiotics.

Foreign body

Sometimes, an object you place in your vagina, including tampons or contraceptive devices, get stuck. Or, you might simply forget they’re in there.

Overtime, the foreign body can cause irritation and infection, leading to unusual-smelling brown discharge. While this discharge typically doesn’t contain any blood, it can closely resemble brown spotting.

Follow up with your healthcare provider for any brown discharge or spotting that’s accompanied by a strange smell. It’s likely a sign of an infection requiring antibiotic treatment.

Polycystic ovary syndrome (PCOS)

PCOS is a condition that causes irregular periods and excess levels of androgen hormones, including testosterone. If you have PCOS, you may not ovulate regularly, or at all.

Without regular ovulation, you’ll likely experience some spotting between your periods.

Other PCOS symptoms include:

  • acne
  • infertility
  • oily skin
  • abnormal hair growth on face, chest or abdomen
  • weight gain

If you think you may have PCOS, make an appointment with your healthcare provider to get a formal diagnosis. If you do have PCOS, there are a range of treatment options available, including lifestyle changes and medication.

Cervical cancer

Cervical cancer can cause vaginal bleeding between periods, even after menopause. Keep in mind that cervical cancer is simply a potential cause of brown spotting, not a likely one.

In addition to brown spotting, you may also have unusual vaginal discharge. It can be foul-smelling, watery, or even blood-tinged. These are usually earlier symptoms of cervical cancer.

Later symptoms include:

  • back pain
  • fatigue
  • pelvic pain
  • problems going to the bathroom
  • unexplained weight loss

Getting regular Pap smears and reporting any unusual symptoms to your doctor are crucial for catching cervical cancer early, when it’s easiest to treat.

Brown spotting can be a completely normal part of your cycle. But if it’s accompanied by any unusual symptoms, especially a fever, unexplained fatigue, or pelvic pain, it’s best to follow up with your healthcare provider.