What Causes Missed Periods Along With Brown Vaginal Discharge?

Hello, I am a 32 year old female that had a litigation 10 year ago and an endometrial ablation 2 1/2 years ago. I never stopped having periods, but they were lighter than usual. I stopped having periods September of 2014 and I didn't have a period for at least 3 months. I took several pregnancy tests and they all came back negative. My body has been going through the motions of pregnancy symptoms. January 1, 2015, I started lightly bleeding for about 3 days and since then, I have had brownish vaginal discharges and have been having light pink streaks of blood after urinating. Is it possible that I am pregnant or is it something worse than it?