Implantation Bleeding

Reviewed by Traci C. Johnson, MD on August 11, 2022


Implantation bleeding is light bleeding from the vagina that happens in some women 10 to 14 days after conceiving 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 feverchills, or have cramps that get worse. 

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
  • Unlike your period, you won’t see any blood clots or tissue in the blood

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

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

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 in pregnant women, 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. Most women bleed and cramp 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. 

Show Sources


March of Dimes: “Pregnancy Complications.”

National Institute of Child Health and Human Development: “What Are Some Common Signs of Pregnancy?”

American College of Obstetricians and Gynecologists: “Abnormal Uterine Bleeding” and “Early Pregnancy Loss.”

Victoria Department of Health & Human Services: “Pregnancy -- bleeding problems.”

UpToDate: “Overview of the etiology and evaluation of vaginal bleeding in pregnant women.”

MemorialCare Health System: “What Color Is Implantation Bleeding? Experts Explain.”

Mayo Clinic: “Bleeding during pregnancy,” “Is Implantation Bleeding Normal in Early Pregnancy.”

University of Rochester Medical Center: “Vaginitis.”

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