What Causes Vaginal Spotting Along With Tingling Sensation In Abdomen?

My last period was Feb 1,2015 I started spotting Mar 16 til Mar 20 the spotting started light pink to reddish from there it went to a brownish /.\ this is the first time this happens to me ;( but its not heavy like my regular period is idk what this means. I ve had this tingly feeling in my stomach can someone help me I don t what this is .