Spotting during pregnancy does not necessarily mean miscarriage. Although spotting can be a sign of miscarriage or ectopic pregnancy, light vaginal bleeding can also occur during viable pregnancies for numerous other reasons.
If you are having spotting during pregnancy, check in with your doctor to have hCG blood tests or an ultrasound to check whether or not the pregnancy is viable. If the spotting is very light and brown in color, this may be implantation bleeding. Spotting that turns into a heavier flow with a red color may be a sign of miscarriage.
Source:
American Pregnancy Association, "Bleeding During Pregnancy." Aug 2007. Accessed 20 Jun 2008.

