Got lower back and lower tummy pains, on n off for days now. And also got mild pains just under my left rib cage. What could it be? I'm worried

May resolve on own.. If the lower abdominal and back pains are too severe, they could be excess gas in the colon causing stretching of the muscles of the gut. Not uncommonly, a gas pocket gets caught in the upper right or left part of the gut and causes pain in the diaphragm just under the rib cage. Try some antacids and anti-gas pills, and perhaps it will resolve in couple days. If not, or becomes severe, see doc.