Implantation Bleeding

Medically Reviewed by Poonam Sachdev on September 07, 2023
Written by Lisa Fields
5 min read

Implantation bleeding is light bleeding from the vagina that happens in some people 10 to 14 days after they conceive a baby.

You may think it’s just a light period, but it’s an early sign of pregnancy. It’s not dangerous, and you don’t need treatment.

But heavy bleeding (more than you’d have with a typical period) can be a sign of a problem. Call your doctor if you bleed a lot, with or without fever or chills, or have cramps that get worse. 

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How common is implantation bleeding?

Implantation bleeding is considered a normal part of pregnancy. About 25% of pregnant people will have it. Some people who do have it might not even notice it.

After a sperm fertilizes your egg, the combination becomes an embryo. It travels to your uterus, where it implants itself into the lining.

Sometimes, as the embryo attaches, it causes a little bleeding. This usually happens about the time you would have your period. You may even confuse it with your period and not realize you’re pregnant. Implantation bleeding is normal and doesn’t mean you or your baby will have problems.

Implantation bleeding tends to happen before you notice morning sickness. You might have:

  • Blood that’s brown or pinkish
  • Blood that’s lighter in flow and doesn’t last as long as your period
  • Mild or no cramping

Implantation bleeding color

This bleeding doesn't look like your monthly period, which is bright red or dark red for most people. Implantation bleeding can range from light pink to brown or dark brown. And it's more like vaginal discharge than your regular period. 

It’s probably implantation bleeding if you have some of the other early signs of pregnancy, including:

  • Tender, swollen breasts or nipples
  •  Fatigue
  •  Headache
  •  Upset stomach
  • Vomiting (morning sickness)
  • Food cravings or aversions
  • Mood swings
  • Peeing more than usual

If you’re not sure whether you’re having implantation bleeding or your period, take a pregnancy test or talk to your doctor.

Pregnancy tests you take at home check for a hormone called hCG in your pee. Your hCG level starts going up after the embryo implants in the wall of your uterus. If you take the test too early, you might get the wrong result. It's a good idea to test 3 to 6 days after the implantation bleeding (spotting) stops. 

Your doctor might give you a blood test that checks for higher levels of hCG. It can find hCG much earlier.

Other than the color of the blood (pink or brownish vs. red or dark red), there are a few other differences between implantation bleeding and a regular period:

  • How long it lasts: Implantation bleeding lasts 1-3 days. Your period normally lasts a week or so.
  • The amount of blood: Implantation bleeding is really just spotting or a very light flow. For your period, you can use several pads and tampons. It starts heavy and decreases as the days go on. 
  • Cramping: With implantation bleeding, you might get very mild cramps, if you get them at all. Cramping for your period can start a day or two before the bleeding starts, and the pain can be intense in some people.

Can implantation bleeding be red?

If your blood is red, it is probably your period or another issue.

Does implantation bleeding have clots?

Implantation bleeding usually doesn't have clots. Some people (but not all) have clots with their regular periods.

Can implantation bleeding be heavy?

Some people think it's a mistake to call it implantation "bleeding" because it is usually spotting or a very light flow at most. Regular periods can be quite heavy, soaking pads and tampons.

Unlike most periods, it usually stops after 1 or 2 days.

It will stop on its own. If you're worried that you've bled a lot, call your doctor. They may want to know how much blood you saw and what color it was.

Many things can cause bleeding when you're pregnant, some of them harmless and some serious. If you’re bleeding a lot, with or without pain or cramping at any time, call your doctor.

If you’re pregnant and see blood in your underwear, it may be caused by:

Sex. Hormonal and physical changes may be to blame for this. It should stop on its own.

Fibroids and polyps. Your doctor might do some tests to check for these growths on your uterus.

Cervical problems. Conditions like infection or growths on your cervix can also cause bleeding.

Infection. Sexually transmitted diseases like trichomoniasis can cause light bleeding as well as more serious problems. Starting treatment as soon as possible will keep your baby healthy.

Ectopic pregnancy. This is when an embryo implants outside your uterus. You may have bleeding with pain and cramps. It’s dangerous and needs medical care right away.

Miscarriage. About 15% of known pregnancies end during the first few months. Bleeding and cramping often happen afterward. Call your doctor right away if you know that you're pregnant and you have these symptoms.

Call your doctor if the bleeding doesn’t stop after a few days or if you’re worried about how much you are bleeding. 

Implantation bleeding happens after an embryo attaches to the wall of your uterus. It is spotting (very light bleeding) that lasts a day or so and is not nearly as heavy as a regular period. 

  • It's very common and stops on its own.
  • One way to know it's implantation bleeding: You may have other early symptoms of pregnancy, such as tender breasts or morning sickness.
  • Wait a few days after the spotting stops to do a home pregnancy test. Your doctor can do a blood test earlier than that to tell you whether you're pregnant.

Can you test positive during implantation bleeding?
 If you take a home pregnancy test during your implantation bleeding, the result is more likely to be negative than positive (even if you are pregnant). The test checks for the amount of the hormone hCG in your pee. But because your body doesn't start making more hCG until the embryo attaches to the uterus, if you take it too soon, the level would still be low. To get a correct result, it's best to wait until a few days after the implantation bleeding stops. If you want results earlier, talk to your doctor about a blood test. HCG will show up faster there.

Can implantation bleeding last 5 days?

Normally, implantation bleeding lasts a day or two. Sometimes it lasts only a few hours. It's rare for it to last more than 3 days. If what seems to be implantation bleeding does go on longer than that, it's probably not implantation bleeding. It might be your regular period or some other issue.