Hello...My question is kind of embarrassing, but I have some concerns. In 2007, I had cancer treatments which included a radical left nephrectomy and radiation therapy . About midway through radiation therapy, my periods stopped. They returned for a short time, during which time I became pregnant, then disappeared again. For four years, I had no periods. They have returned, they are irregular, my menstrual blood smells like sulphur, and I ve been getting killer migraines. Any idea what s going on?