What Causes Brown Vaginal Discharge While On Treatment For Endometriosis?

Hi my name is Heather, I had a laposcopic surgery done September 9th 2014 and was dignosed with Endometriosis. I have been receiving treatment for just about 6 months.. March 23rd 2015 will be my 5th injection of Lupron Depo.. I have not had a period due to the injection stopping my period for the duration of my treatment.. During my treatment I have had some brown break threw bleeding which I was told by my doctor was normal in the begining of the treatments.. well..about 4-5 days ago I woke up with brown blood in my panties accompanied by bad adominal and pelvis cramping that makes me not be able to move and is a sharp but dull cramping deep within my pelvis right under my actual stomach.. it radiates to my buttox bone and I have bad lower back pains as well...The bleeding is not light or heavy but medium.. I go threw at least 2-3 pads.. when I wip after a visit to the bathroom there s a good amount on the tissue paper as well as the linning from the egg as seen when you have a period... my doctor told me Im not supposed to have bleeding now that I am so far along in treatments.. There is no iching, burning or fowel smell.. I m worried it could be a misscarrage or verginal hemorrhage help please!