Pregnancy occurs when a sperm cell fertilizes an egg in the fallopian tube. The fertilized egg then travels to the uterus. It takes approximately 10 to 14 days between egg fertilization, or conception, and implantation into the uterus wall. A woman often doesn't realize implantation has taken place, but sometimes signs and symptoms develop.
Hormonal changes may cause a host of symptoms that signal possible pregnancy. Some are similar to those that occur with premenstrual syndrome, or PMS, so women may not be sure whether the symptoms are part of their normal cycle or signal pregnancy. Light spotting, or implantation bleeding, is one symptom they may notice.2‘Early Pregnancy: Signs & Verification Services.’ UPMC, www.upmc.com/services/south-central-pa/women/services/pregnancy-childbirth/getting-pregnant/early-pregnancy.
1. Implantation Bleeding: Color and Clotting
Up to 25 percent of women experience slight bleeding or spotting during early pregnancy.3‘What Are Some Common Signs of Pregnancy?’ Eunice Kennedy Shriver National Institute of Child Health and Human Development, U.S. Department of Health and Human Services, www.nichd.nih.gov/health/topics/pregnancy/conditioninfo/signs. If implantation bleeding occurs, its color typically ranges from light pink to dark brown. In contrast, the color of the blood present during regular monthly periods is usually bright to dark red. Some women notice clotting during normal menstruation, while others have no clotting. Implantation bleeding doesn't produce clotting.4‘What Is Implantation Bleeding?’ American Pregnancy Association, 23 Oct. 2020, americanpregnancy.org/pregnancy-symptoms/what-is-implantation-bleeding-24176.
The cervix is more prone to bleeding during early pregnancy, so it's not unusual for spotting to occur following sexual intercourse, a pelvic exam or a pap test.5‘Bleeding During Pregnancy.’ ACOG, www.acog.org/womens-health/faqs/bleeding-during-pregnancy.