What Causes Brownish Bleeding?

Hi. I am little confused what is going on with me. First of all I haven t been to gyn for about 6 years and my husband had his vastecmony in about 15 years ago. I have 3 children of my own. I have had a brownish bleeding on the 31st.( New Years Eve) then it stopped until yesterday again light brownish bleeding. My first day of my last period was on Nov. 17th then brownish bleeding for a day on the 31st. Do you know what this sign means?