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Breakthrough bleeding, aka “spotting,” is any unexpected bleeding you experience between periods — and yes, breakthrough bleeding can happen even when you’re on the pill.

If this has happened or is happening to you, fear not. Breakthrough bleeding is the most common side effect of oral contraceptives, especially within the first 3 months of taking them. Spotting can also happen when you switch from one pill to another with a different amount of estrogen.

Breakthrough bleeding typically doesn’t look like a normal flow — it’s usually very dark or light in color, like the blood at the beginning or end of your period. But it can sometimes be very difficult to distinguish between the two.

While breakthrough bleeding usually isn’t a reason to panic, it can sometimes indicate a bigger issue. Let’s learn how to spot (pun intended) the difference, shall we?

Different hormonal and lifestyle factors can contribute to breakthrough bleeding. While some of the causes may be unavoidable, others can be managed more easily.

Combination oral contraceptives

Combination oral contraceptives contain a mix of synthetic estrogen and progestin. They’re the most frequently prescribed type of birth control pill.

These pills work by manipulating your body’s hormone levels to keep your ovaries from releasing an egg. The levels of progestin and estrogen vary from pill to pill.

Thirty to 50 percent of women using combination pills will have some breakthrough bleeding within the first 6 months of use. After the first 90 days, it’s less common, affecting 10 to 30 percent of users. Breakthrough bleeding is more often associated with low-estrogen pills.

No estrogen allowed — spotting still welcome

While breakthrough bleeding is more common with low-estrogen pills, it can still happen if you’re taking a progestin-only pill, aka “minipill.” In fact, it’s the most common side effect of this kind of birth control.

Progestin-only oral contraceptives are a preferred option for women who can’t take estrogen because of underlying health risks. This includes women over 35 who smoke and those with a history of deep vein thrombosis (DVT).

Unlike combination pills, a minipill regimen has no placebo days. As a result, women taking it may never get their period.

FYI:

Breakthrough bleeding is much less predictable with progestin-only pills than with combination oral contraceptives.

Continuous birth control pills

Continuous birth control pills (like Seasonale and Seasonique) are a type of combination oral contraceptive, which means they contain both synthetic estrogen and progestin.

But unlike traditional combination pills, which typically have 21 active pills and 7 placebo pills in a pack, continuous birth control pill packs have no placebo days for months at a time.

Having fewer “off-days” means more synthetic hormones are circulating in your body and preventing your ovaries from releasing an egg, so your period will be shorter. In fact, you may not get your period at all.

While continuous birth control pills shorten your menstrual cycle, they are associated with more frequent incidents of breakthrough bleeding than their traditional combination pill cousins.

Dose MIA

Forgetting to take your birth control pill for even one day can trigger hormone fluctuations, which can cause breakthrough bleeding. Be consistent if you’d like to avoid any unexpected events in your pants.

If you’re on the minipill, it’s especially important to take the pill at the same time every day. But it’s best to stick to the same time even if you’re on a combination pill.

IUDs

An intrauterine device (IUD) offers another excellent form of birth control for those who aren’t fans of taking a pill. There are two kinds of IUDs: copper and hormonal.

Copper IUDs like Paragard work by provoking an inflammatory response in your uterine lining, which makes it inhospitable to implantation — not to mention that copper is toxic to sperm.

Hormonal IUDs like Mirena work by releasing progestin into your system. Progestin weakens your uterine lining, making it harder for sperm to get around. It also thickens cervical mucus and can prevent ovulation.

As many as 70 percent of new users will experience breakthrough bleeding and/or heavier periods with a copper IUD, especially within the first 3 to 6 months.

Hormonal IUDs are typically associated with lighter, shorter periods in the long run, but breakthrough bleeding is also common within the first 3 to 6 months after insertion.

Puff, puff, spot

Smoking significantly increases the risk of breakthrough bleeding while on the pill. It also increases the risk of other serious side effects like heart attack and stroke.

Your supplement may be to blame

Other medications and supplements can cause breakthrough bleeding. If you’re on the pill, it’s especially important to talk to your doctor about any other medications or supplements you’re taking, no matter how “natural” they may be.

Some common offenders when it comes to breakthrough bleeding include:

Chronic diarrhea or vomiting

If you deal with chronic diarrhea or vomiting, your body may not be absorbing a consistent dose of hormones from your birth control pills. This kind of hormone fluctuation can trigger breakthrough bleeding, but it can also make your BC pills ineffective, so take precautions.

Folks with gastrointestinal disorders like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are at higher risk for this kind of breakthrough bleeding.

Breakthrough bleeding usually stops within 3 to 6 months of starting a birth control pill regimen, but it can take a little longer with continuous birth control pills or if you often miss doses. Consistency and a little patience are key.

If you’re not the most organized person in the world, it may be worth setting a daily alarm to get into the habit of taking your pill every day.

On the other hand, if you take your pill like clockwork and you’re still experiencing breakthrough bleeding, your doctor may prescribe supplemental estrogen or a low-dose pill to help regulate things.

Breakthrough bleeding may signal an underlying medical problem. Here are some other causes to consider:

Fibroids

Uterine fibroids can also cause breakthrough bleeding. But these growths have more to do with genetics than hormones.

Infections

Breakthrough bleeding can be the result of a sexually transmitted infection like gonorrhea or chlamydia. Some preexisting medical conditions can also cause breakthrough bleeding.

Common culprits include:

  • vaginitis
  • pelvic inflammatory disease (PID)
  • endometritis
  • cervicitis

If your breakthrough bleeding is associated with any of the following symptoms, it could be the sign of an infection. You should talk to your doctor immediately to avoid further complications:

  • cloudy urine
  • abnormal vaginal discharge
  • foul odor
  • pelvic pain or burning

Endometriosis

Spotting or bleeding between periods can be a symptom of endometriosis, a condition in which the lining of the uterus grows in other places in the body.

If your breakthrough bleeding is accompanied by any of the following symptoms, talk to your doctor ASAP:

  • intense cramps
  • lower abdominal pain
  • pain during sex
  • pain when using the bathroom during your period
  • especially heavy periods

You may not be sensitive, but your cervix is

If you have a sensitive cervix, you may be more susceptible to injury or irritation that can cause spotting. This isn’t always something to worry about, but if you’re concerned, talk to your doc.

Breakthrough bleeding is one of the early signs of pregnancy, but spotting can also happen later in pregnancy. While breakthrough bleeding can certainly be alarming if you’re pregnant, it’s not always a sign of something serious.

Implantation bleeding

Implantation bleeding typically occurs in the first 2 weeks after conception, but not all women experience it.

While implantation bleeding is typically light enough not to require a pad or tampon, it can be difficult to distinguish from a normal period or other kinds of breakthrough bleeding. When in doubt, a pregnancy test is your best friend.

Spotting in pregnancy

There are a few reasons you might experience spotting during pregnancy, and while some forms are benign, others can be more serious.

Subchorionic hematoma

A subchorionic hematoma is a condition in which the chorionic membranes separate from the sac between the uterus and the placenta. This sometimes causes clots and bleeding in varying amounts.

While most hematomas are nothing to worry about, you should always see your doctor for a proper diagnosis and to discuss next steps (if any).

Miscarriage and ectopic pregnancy

In some serious cases, breakthrough bleeding can be a sign of ectopic pregnancy or miscarriage.

Ectopic pregnancy occurs when an embryo implants in the fallopian tube rather than the uterus. A miscarriage is when a fetus dies before the 20th week of pregnancy.

Ectopic pregnancy is a serious condition and usually requires surgery. Bleeding caused by a miscarriage can last about 3 weeks.

If your breakthrough bleeding is heavy or comes along with any of the following symptoms, call your doctor right away:

  • dizziness
  • abdominal cramping or pain, especially if it’s severe
  • any of the symptoms associated with infection or other medical conditions mentioned above

Breakthrough bleeding — while on the pill or otherwise — can be frustrating or worrisome, but it’s not always a sign of something serious.

If you take birth control pills, do yourself a favor and be consistent about it. Otherwise, pay attention to any unusual symptoms, and when in doubt, dial your doc’s office.