Ihave a pain on my lower abdmion on the left?

Various: We do not know age & that helps. Assuming you are on younger side of life, & assuming this is a lingering & chronic pain, causes could be kidney infection, constipation, orarian mass, hernia, pelvic girdle disorder, muscle spasm of abdominal wall muscle, or pinched nerve. If develop fever & vomiting see a doctor emergently. See a family doctor or a general surgeon, they are good at diagnosis.