What would cause my lower left side of my abdomen to hurt? i'm going on day 2 now of pain and it feels worse that it did yesterday.

And pain: If the pain seems to run into the groin area think of a kidney stone. If the pain is more localized a colitis or diverticulitis could be the cause. More likely to have a fever with either of these. If the pain is getting worse as you said, then an evaluation is in order. See your PCP.

Progressive pain: Many things can cause lower abdominal pain in a man. Since the pain is progressive you will need to have an evaluation ASAP. The physician will perform an exam, do lab tests, and probably order a CT scan (detailed imaging of your abdomen). Go right away - Good luck.