Spotting refers to any light bleeding outside of your typical menstrual period. It usually isn’t serious and looks like small spots of pink or red on your underwear, toilet paper, or cloth.

Since spotting can be so similar to typical period stains, identifying other symptoms can help you determine its cause.

Here’s what to watch for and when to see your doctor.

Periods often have a few days of light bleeding and a few days of heavier bleeding. Many people bleed lightly at the beginning and end of their period. This will look about the same as your normal period blood. Period blood often changes in color, consistency, and flow from one day to the next.

You may have spotting for a few days leading up to your period while your uterus prepares to shed its lining. After your period, the bleeding may taper off slowly. You may only notice a little blood on the toilet paper you use to wipe, or you may see stains accumulate on your underwear throughout the day. This is all considered normal.

Other signs that you’re beginning or ending your period include:

  • sore or swollen breasts
  • cramps
  • lower back pain
  • moodiness

When you’re ovulating, your estrogen levels peak and then decline. In some women, estrogen levels drop drastically after ovulation. A quick drop in estrogen can cause your uterine lining to begin shedding.

Spotting may continue until your hormones stabilize — typically within a few days.

Other signs of ovulation include:

  • thin, watery vaginal discharge
  • discharge that looks like egg whites
  • bloating
  • breast tenderness

Spotting is very common when starting a new method of birth control. That’s because the change in hormone levels affects the stability of your uterine lining.

It doesn’t matter whether you’re starting hormonal birth control for the first time, switching between different forms of hormonal birth control, or switching from hormonal birth control to nonhormonal birth control — spotting is bound to happen.

It may look like period blood or blood mixed with normal vaginal discharge. Most people can put a panty liner on in the morning and wear it all day without experiencing leakage.

Spotting may happen on and off until your body adjusts to the change in hormone levels — usually up to three months.

Other side effects include:

  • irregular periods
  • cramping
  • headaches
  • nausea

The “morning-after pill” is an emergency contraceptive that contains a high dose of hormones. Most emergency contraceptives work by delaying ovulation.

This can interrupt your normal menstrual cycle and cause some spotting. Small amounts of red or brown discharge may occur daily or every few days until your next period. Your next period may arrive on time or come a week early.

Other side effects include:

  • headache
  • tiredness
  • abdominal pain
  • dizziness
  • nausea
  • sore breasts

Implantation occurs when a fertilized egg embeds itself into the lining of your uterus. This typically happens one to two weeks after conception and may cause spotting. Spotting should only last a few days. You may also experience minor cramping.

If the pregnancy continues, you may go on to experience minor spotting throughout the first trimester.

An ectopic pregnancy occurs when a fertilized egg implants itself into tissue outside of your uterus.

Ectopic pregnancies can cause spotting before you even know you’re pregnant.

Other signs of an ectopic pregnancy include:

  • abdominal pain
  • pelvic discomfort
  • sudden dizziness
  • severe abdominal pain
  • missed period

If you suspect an ectopic pregnancy, seek immediate medical attention. Ectopic pregnancies can cause life-threatening internal bleeding if left untreated.

Perimenopause is the time leading up to your final period. You’ll reach menopause when you’ve gone 12 months without a period.

Until then, you may experience spotting, missed periods, long stretches of time between periods, and other irregularities. These changes are a result of your fluctuating hormone levels.

In some cases, spotting can also be caused by:

  • Hormonal imbalance. When your hormones get off kilter, it can cause irregular periods and spotting.
  • Stress. When your stress levels go up, your hormones can get out of whack.
  • Vaginal dryness. Vaginal dryness can happen when your estrogen levels drop.
  • Rough masturbation or sex. Rough sex play can injure the tissue inside the vagina and around the vulva.
  • Cysts. Ovarian cysts develop when a follicle fails to release an egg and continues to grow.
  • Fibroids. Fibroids are noncancerous growths that develop in or on the surface of the uterus.
  • Pelvic inflammatory disease (PID) and other infections. PID is an infection of the reproductive organs, often caused by common sexually transmitted infections like chlamydia and gonorrhea.
  • Thyroid disorders. Thyroid disorders occur when your body produces too much or too little thyroid hormone, which plays a role in your menstrual cycle.

Although spotting usually isn’t anything to worry about, you should see a health practitioner if it persists for more than two or three months. They’ll perform a physical exam, pelvic exam, or Pap smear to assess your symptoms and determine the underlying cause.

You should seek immediate medical attention if you’re experiencing abnormally heavy bleeding or severe pelvic pain. These could be signs of an ectopic pregnancy, which is a potentially life-threatening condition.

Those in menopause should always follow up with a healthcare practitioner if they experience spotting. It can be an early sign of uterine cancer and other vaginal diseases.