Implantation bleeding — typically defined as bleeding that occurs 10 to 14 days after conception — is normal and relatively common.
Implantation bleeding is thought to happen when the fertilized egg attaches to the lining of the uterus. Implantation bleeding usually occurs around the time you would expect to have a menstrual period. However, implantation bleeding generally lasts for a short time and is usually much lighter than menstrual bleeding.
Some women don't experience implantation bleeding and others don't notice it. It's also possible to mistake implantation bleeding for a period. If this happens, you might not realize that you're pregnant — which can lead to mistakes when determining a baby's due date.
Implantation bleeding stops on its own and doesn't require treatment. If the bleeding persists or you're concerned about any vaginal bleeding during pregnancy, contact your health care provider.