Pain in the left lower side of stomach may be due to many reasons like Left ureteric stone,Infection of large intestine,Pelvic inflammatory disease
,Left Ovarian cyst
If the pain is not relieved by Antibiotics and Anti inflammatory drugs,then you should be investigated.
Plain x ray
abdomen and Ultrasound
abdomen will give a Clue to the disease.
Please get them done with the advice of your doctor.
Hope everything will be fine
All the best