Dull intermittent pain in lower left abdomen (very low) started last night and continued today. what might it be. no fever and no vomiting?

Possibilities: Possibilities are diverticular disease, ovarian cysts or other problems, uterine fibroids, even bladder trouble. If your symptoms change with a bowel movement then that makes an problem with your colon more likely. If you do develop fevers you should be seen right away as that might indicate diverticulitis (infection of a diverticulum) which needs antibiotics. An ultrasound might be helpful.