Although pregnant women do not menstruate, some experience vaginal bleeding in early pregnancy that is often mistaken for a period. In fact, approximately one-quarter of pregnant women experience bleeding in the first trimester, according to Marjorie Greenfield, M.D., contributor to DrSpock.com. Since doctors use the date of the last menstrual period to determine a due date for a pregnancy, it is important for women to learn when they may be pregnant despite their vaginal bleeding.
Analyze the bleeding. Vaginal bleeding that is light and occurs shortly before an expected period may be something called implantation spotting. Implantation spotting occurs when an embryo implants into the lining of the uterus. If the vaginal bleeding was much heavier than normal, it may be a sign of a serious medical condition.
Women should make a note of the color and flow of the bleeding and any other symptoms they experienced with the bleeding. They should also consider if the bleeding occurred at the same time as their expected period or if it occurred before or after it.
Check for early pregnancy signs. Many women experience specific symptoms early in pregnancy, including fatigue, nausea, swollen or tender breasts, frequent urination, darkening of the areolas on the breast and headaches, explains the American Pregnancy Association. Although women can experience these symptoms without being pregnant, having many of these symptoms may indicate a pregnancy is likely.
Take a pregnancy test. Although most women can use a home pregnancy test to determine if they are pregnant, women who have experienced vaginal bleeding may want to consider going to the doctor and getting a beta hCG test, also referred to as a quantitative blood pregnancy test. This test can detect pregnancy just 10 days after conception, according to the National Institutes of Health, and tends to be more accurate than home pregnancy test.
Talk to a doctor. Regardless of the results of the pregnancy test, women who had unusual vaginal bleeding should always discuss the bleeding with a doctor.
Although the expected due date of a pregnancy normally is calculated based upon the last menstrual period, women who experience vaginal bleeding during pregnancy may not be sure of when their last menstrual period occurred. It may be necessary for these women to calculate the due date of the pregnancy by an ultrasound instead.
In addition to normal menstruation, medical conditions including infections of the uterus or cervix, problems with birth control, fibroids or polyps, problems with blood clotting and cancer of a reproductive organ, may cause vaginal bleeding, according to the American Congress of Obstetricians and Gynecologists. Women who experience vaginal bleeding that is different from their usual period should always talk to a doctor.