Here's some advice from the MedHelp website and our I'm Expecting app on spotting during pregnancy.
http://www.medhelp.org/pregnancy-health/articles/Spotting-and-Vaginal-Bleeding-During-Pregnancy-Your-Symptoms-Manual/1980
You can find this in the app by going to the Pregnancy Diary from the home screen and selecting Spotting from the Symptoms menu. Then click the menu bar in the upper left and select Symptoms Manual to see your symptoms.
Call your doctor right away or go to emergency room, it can be very normal, but always have double check . Cause bleeding isn't always a good or bad thing. God bless you and the baby.