Implantation Bleeding or Miscarriage

Determining the Cause of Light Bleeding

Pregnant African American woman holding her stomach in hospital
Jose Luis Pelaez Inc / Getty Images

Did you notice a smear of blood on your underwear or toilet paper soon before or right around the time you found out you were pregnant?

You may have experienced implantation bleeding, which is a small amount of vaginal bleeding that occurs in some women around ten days after conception. The bleeding signals that a fertilized egg has implanted or attached to the wall of a woman's uterus.


There's not a lot of research about the exact reasons why some women have this bleeding and others do not, or why a woman will experience implantation bleeding during one pregnancy and not another. Regardless, it's important to note that implantation bleeding is no cause for concern and does not affect the viability of a pregnancy. Similarly, not having implantation bleeding is OK and should not worry you. 

Taking a Pregnancy Test If You Suspect Implantation Bleeding

Implantation bleeding typically occurs within one to two weeks after fertilization, which is often close to the time that a woman expects her monthly period. Due to this timing, implantation bleeding could be mistaken for an extremely light menstrual period in some women, especially in women who normally have light menstrual flows. A woman may the engage in behaviors that may affect the developing fetus (baby) like smoking, drinking alcohol, or taking certain medications because she does not believe she is pregnant.

With that, if you have unusually light bleeding around the time of your menstrual period and the bleeding does not turn into a heavier, normal flow, it's a good idea to take a pregnancy test. A few spots of blood or a light flow should not be taken as proof of a period and a sign that you are not pregnant—you could be, as this spotting may be implantation bleeding.

Distinguishing Implantation Bleeding From an Early Miscarriage

Distinguishing implantation bleeding from an early miscarriage bleeding can be confusing as well. In general, bleeding associated with an impending miscarriage or chemical pregnancy may begin as spotting but then turn into a heavier flow with visible clots and a dark red color (similar to a menstrual period). Cramping and passing tissue through the vagina are other signs of a miscarriage.

In contrast, implantation bleeding may appear as a brown or lighter colored discharge without clots with a lighter flow that lasts only a few hours to a few days.

Neither rule is universally true, however, and the best way to determine the cause of early pregnancy bleeding is to visit your doctor for an hCG blood test or an early pregnancy ultrasound, in addition to a thorough medical history and physical examination.

The pregnancy hormone human chorionic gonadotropin (hCG) is made by the placenta after the fertilized egg implants into the lining of the uterus. This can occur as early as eight days after conception.

With ultrasound, a gestational sac becomes visible around five weeks after a woman's last menstrual cycle (if pregnancy) and an embryo or fetal pole is visible at the end of the sixth week.

Other Causes of Vaginal Bleeding During Early Pregnancy

Besides an early miscarriage, vaginal bleeding during pregnancy may be a sign of an infection of the cervix, vagina, or urinary tract. Some women who are pregnant also experience bleeding after sex or after a pelvic exam, due to the development of blood vessels in the cervix.

Vaginal bleeding may also be a sign of an ectopic pregnancy, which occurs when a fertilized egg implants into one of the fallopian tubes and not the lining of the uterus. This is dangerous because the fallopian tube can tear open and cause internal bleeding.

While vaginal bleeding may be the only sign of an ectopic pregnancy, other symptoms may include pain in the abdomen, pelvis, or even shoulder.

Seeking medical attention is important if you are experiencing these symptoms. The fertilized egg cannot live in the fallopian tube and needs to be removed with surgery or medication.

A Word From Verywell

If you are experiencing any vaginal bleeding during pregnancy, it's important to contact your health care provider. While it's natural to worry about a possible miscarriage, there could be a number of reasons why you experienced spotting in early pregnancy including harmless ones like implantation bleeding or bleeding after having sex. Your doctor can help you sort it out, so you can move forward.


Bleeding During Pregnancy. American College of Obstetrics and Gynecologists.

Bleeding During Pregnancy. American Pregnancy Association.

Deutchman M, Tubay AT. First Trimester Bleeding. Am Fam Physician. 2009 Jun 1;79(11):985-92.

What is Implantation Bleeding? American Pregnancy Association.