I have a tiny kidney stone. I am experiencing a sharp, moderate pain in the pelvis and pain with urination. Could the kidney stone be causing this?

Yes. Hello,You don't say what "tiny" measures,but a small kidney stone may have passed down the ureter and giving you pelvic pain and pain on urination if it is stuck at the uretero-vesical junction(ureter-bladder connection point).A plain Xray will help.Make sure you strain your urine and follow your doctor's advice.Hope this helps and get well soon.
Yes . If the stone decided to drop from the kidney to the ureter which connects the kidney to the bladder, you could be experiencing these symptoms. If it is truly a small stone, less than 3 mm, you should pass it in a few days. If there is doubt to the cause, your physician can order a ct scan which should show if the kidney is obstructed by the stone.
Urine infection. A urinary tract infection seems more likely. Having a stone makes you prone to get urine infections. A simple urine culture is diagnostic. Kidney stones cause pain only when they are blocking flow of urine especially in the ureter which is the tube connecting the kidney to bladder. This type of pain is crampy and very severe associated with vomiting.