If you are thinking of UTI,check for its signs and go for urine test:
The urge to urinate frequently, which may recur immediately after the bladder is emptied.
A painful burning sensation when urinating.
Discomfort or pressure in the lower abdomen. The abdomen can feel bloated.
Pain in the pelvic area or back.
OR it could be due to other reasons also like appendicitis
OR Infection in the Kidney
So,consult your Doctor for the diagnosis.