What is going on with me?

Ok so this is a difficult one to *****. About two and a half months ago I had to have my galbladder taken out. My Doctor has said that I did fine with the surgery and that I am all better. Ok then about a month and a half ago my life became very stressful and I lost my very close Uncle to a heart attack and on the same day ended a 6 year relationship with my childrens father. I have had a tough time dealing with the stress of being a single parent and not having my best friend around, but I am managing. Anyway last month my cycle was kinda fwierd. It was really sparatic and light at times and then heavy at times and only lasted a few days. This is a little unusual but my periods have always been just a little unpredictable so I didnt really think anything of it at the time. Now this month I have still not got my period at all. I was supposed to get it around the 7th of the month and it is the 27th. I have taken 2 pregnancy tests and they both have come back negative. I recently lost 24 pounds in like a month and a half and I know that may have something to do with it as well. I was not increadably worried until last night when I went to the bathroom and I had a thick dark brownish red discharge. I thought maybe I was getting my period but it only came out a little and after I cleaned the area has not returned. It was not a normal thing to come out of a person though and I know there has to be a cause. Please help with any ideas you may have!!