I do not have pelvic endometriosis. I have regular periods with normal groin and lower abdomen pain. Periods last for 4 days. Recently i have noticed that only during periods i have right upper abdominal rib pain , pain behind right breast, chest, lungs, sternum, back , neck, arm. I have no breathing difficulty or any cough, just the pain during period. It goes away after periods are over and comes back again 5 days before period. Can it be Thoracic endometriosis?? My chest Xray is nromal. Pelvic MRI is normal