What Causes Irregular Menstruation And Prolonged Vaginal Discharge?

Hi I am 39 years old and I am experiencing vaginal discharge of brown color sometimes red for almost 1 1/2 month now and I have a light period now but I have a regular monthly period 26 days cyle in a month. I am married but no child at all.. this is the first time happen to me.. and I check if I am pregnant but its negative.. but I was delayed last month on my period because of maybe stress. now I am worried because of this discharge. and I am not experiencing any pain in my pelvic and in my abdomen.. cna you help me doc.