What Causes Severe Abdominal Cramps And Abnormal Menstrual Discharge?

I went gor my psp, came normal.
Since i was having premenpausal symptoms I had an ultrasound , ultrasound was fine, showing same tiny fibroids from before. Blood Work showed levels are normal for menopausal woman. My period has been gone since October. Last night I stared to brown spot. This morning I woke up cause of the cramps, so strong it felt I was in labor. I had blood discharge, cramps don't go away. But now no more blood, just brown when I wipe.