Any kind of bleeding or spotting during pregnancy can feel scary, especially if you have a history of miscarriage. If you are having brown spotting that is light in quantity, however, don't panic yet. Researchers have found that as many as 20% to 40% of all viable pregnancies have some level of bleeding or spotting in the early stages.
The seriousness of spotting in early pregnancy appears to depend on the quantity and color of the bleeding. Heavier, red-colored bleeding that includes clots means a higher likelihood of miscarriage, and moderate to severe cramping along with spotting also indicates a lower odds of a good outcome. Light brown spotting that isn't accompanied by significant pain is less likely to indicate a problem, although any bleeding or cramping in pregnancy is worth mentioning to your doctor or midwife.
Source:
Norwitz, Errol R, and Joong Shin Park. "Overview of the etiology and evaluation of vaginal bleeding in pregnant women." UpToDate. Last literature review version 17.2: May 2009.
