What Does Brownish Spotting From Vagina Indicate?

I had a total abdominal hysterectomy, removal of ovaries/tube, omentum, lymph nodes, biopsies of my bladder, gut, pelvis, and other lymph nodes four months ago for ovarian cancer contained in my left ovary, I saw a little brownish spotting coming from my vagina. What does that mean? It frightens me.