Why Am I Bleeding 6 Days After Taking Plan B?

Bleeding six days after taking Plan B is common and usually a normal side effect of the emergency contraceptive pill. This bleeding is not your period. It is a withdrawal bleed caused by the sudden drop in hormones after you take the medication. Plan B works by delivering a high dose of levonorgestrel, a synthetic hormone, to delay or prevent ovulation. When your body clears that hormone, the uterine lining can shed early. This is not a sign of injury or failure. It is a predictable response to a large hormonal shift.

What Exactly Causes Bleeding After Plan B?

Plan B contains a high dose of levonorgestrel, which is a progestin hormone. Your body is not used to this sudden spike. The hormone causes changes in the lining of your uterus, called the endometrium. When the hormone level drops quickly, the lining can break down and shed. This is the same mechanism that happens at the end of a normal menstrual cycle when your own progesterone levels fall.

The difference is timing. A normal period happens roughly every 28 days. Plan B forces this shedding to happen at an unpredictable time. For many women, this happens about a week after taking the pill. Some women bleed sooner, some later, and some do not bleed at all. All of these can be normal.

Research shows that up to 20 percent of women experience some form of bleeding within seven days of taking levonorgestrel emergency contraception. This number comes from clinical trials and large observational studies. The bleeding is typically light, like spotting, but it can be heavier for some women. It rarely requires a pad or tampon change more than once every few hours.

Is This Bleeding My Period or Something Else?

This is almost certainly not your period. A true period happens roughly two weeks after ovulation. Plan B works by delaying ovulation. If you took Plan B, ovulation likely did not happen yet, or it was delayed. Without ovulation, there is no normal menstrual cycle to follow. The bleeding you see is a drug-induced withdrawal bleed, not a true menstruation.

Your next real period will probably come later than expected. Studies have found that about 15 percent of women have their next period more than seven days late. This is not a sign of pregnancy. It is simply your body resetting its cycle after the hormonal disruption. Your period may also be lighter or heavier than usual for one cycle.

If you are tracking your cycles, do not mark this bleeding as day one of your next cycle. It is not. Your cycle restarts when your real period comes. If you are using a period tracking app, log this as spotting or withdrawal bleeding, not menstruation. Otherwise, your app will predict your next ovulation incorrectly.

How Heavy Should the Bleeding Be?

Most women report light to moderate bleeding. This means spotting that does not soak through a panty liner or light pad. Some women describe it as brown or pink discharge. Others see bright red blood. The color is not important. What matters is the volume and duration.

Normal bleeding after Plan B lasts one to three days. Some women spot for up to a week. Heavy bleeding that soaks through a pad or tampon every hour for more than two hours is not normal. Neither is bleeding that lasts more than seven days. These situations warrant a call to your healthcare provider.

Here is a quick guide to what is typical versus what needs attention:

Does Bleeding Mean Plan B Worked?

Bleeding does not confirm that Plan B prevented pregnancy. The bleeding is a side effect of the drug, not proof that ovulation was blocked. Some women bleed and still ovulate later. Some women do not bleed at all and still avoid pregnancy. The two events are not directly linked.

What does confirm effectiveness is timing. Plan B works best when taken within 72 hours of unprotected sex. The sooner you take it, the better. If you took it within 24 hours, it prevents about 95 percent of pregnancies. If you took it between 48 and 72 hours, effectiveness drops to about 85 percent. These numbers come from the original clinical trials published in the late 1990s and confirmed by later studies.

Bleeding or not bleeding tells you nothing about whether those numbers applied to you. The only way to know if Plan B worked is to wait for your next period or take a pregnancy test. If your period is more than seven days late, take a test. Do not rely on spotting or bleeding as a sign of success or failure.

Can Plan B Cause Other Side Effects Besides Bleeding?

Yes. Bleeding is just one of several possible side effects. Many women also experience nausea, headache, breast tenderness, dizziness, or fatigue. These symptoms are caused by the same hormonal surge that triggers the bleeding. They usually resolve within 24 to 48 hours.

Nausea is the most common side effect. About one in four women feel nauseous after taking Plan B. Vomiting is less common but happens in about 5 percent of women. If you vomit within two hours of taking the pill, it may not have been fully absorbed. In that case, you should contact your doctor or pharmacist about repeating the dose.

Some women report mood changes or anxiety. This is not well studied in clinical trials, but many women report it anecdotally. The hormone dose in Plan B is much higher than in daily birth control pills. It is not surprising that some women feel emotional or irritable for a day or two. Current research suggests these mood effects are short-lived and do not cause long-term changes.

Why Am I Bleeding 6 Days After Taking Plan B and Not Earlier or Later?

The six-day mark is common because of how your body metabolizes levonorgestrel. The drug reaches its peak concentration in your blood about two hours after you take it. Your liver then starts breaking it down. The half-life of levonorgestrel is about 24 hours. This means half the drug is gone after one day, half of what remains after two days, and so on.

By day five or six, most of the drug has left your system. Your uterine lining, which was stabilized by the high hormone level, no longer has that support. It begins to break down. This timing explains why bleeding on day six is so common. It is not random. It is the predictable result of the drug leaving your body.

This also explains why some women bleed earlier or later. If your metabolism is faster, you might bleed on day four. If it is slower, you might not bleed until day eight. Your body weight, liver function, and other medications can all affect how quickly you clear the drug. None of these variations are dangerous.

As of 2026, there is no clinical evidence that bleeding on day six specifically means anything different from bleeding on day three or day nine. It is all the same process happening on a slightly different schedule.

When Should I Worry About Bleeding After Plan B?

Most bleeding after Plan B is harmless. But there are situations where you should seek medical attention. If the bleeding is very heavy, meaning you soak through a pad or tampon every hour for two or more hours, call your doctor. This could indicate a complication like an ectopic pregnancy or a uterine issue unrelated to the pill.

Severe pain is another red flag. Mild cramping is normal. Pain that stops you from standing up straight or that radiates to your shoulder or back is not. This can be a sign of an ectopic pregnancy, where a fertilized egg implants outside the uterus. Plan B does not cause ectopic pregnancy, but if you were already pregnant before taking Plan B, the pill will not work. An ectopic pregnancy is a medical emergency.

Other warning signs include fever, chills, or foul-smelling discharge. These suggest an infection, not a side effect of the pill. Plan B does not cause infections. If you have these symptoms, see a doctor promptly.