Low back pain. ..Bleeding on and off for a month...Tubes tied...Cramping/pain in low stomach area...What could be?

Pregnant after BTL. Even after a tubal, there is a failure rate of 4-7/1000. If irregular bleeding, pain, consider the option that it could be pregnancy. After a tubal, if a pregnancy does occur, there's an increased likelihood of ectopic pregnancy. Other than pregnancy, other causes of pain and bleeding include polyps, endometriosis, and adenomyosis.