Hi,
Minor pain in left side of abdomen is usually nothing to worry about and may subside on its own in a day or two. Left sided 
abdominal pain may result from 
diverticulitis, constipation, gas, indigestion, kidney stones, dysmenorrhoea or 
menstrual cramps, 
endometriosis, ovarian cyst, ovarian torsion, ectopic pregnancy, 
pelvic inflammatory disease (PID), hernia etc.Treatment depends on causes. Some investigations like CBC with ESR, Urine R/M/E, USG of abdomen, CT scan or MRI abdomen, Endoscopy of upper GIT etc to find out the exact causes for abdominal pain and then treat them accordingly. 
Take care. Hope I have answered your question. Let me know if I can assist you further. 
Regards, 
Dr. Zubayer Alam, General And Family Physician,