This could be an infection in the kidneys or kidney stones too.
UTI or urinary tract infection is due to undue growth of microbes in the urinary pathway.
This may be caused by spread of infection from a nidus of infection in the tract, from blood or from some other adjacent infectious tissue.
Bladder infection may result in symptoms of urination, frequency urgency etc with fever and lower abdominal pain.
Kidney infection may result in symptoms of pain in the loins, fever, and urinary symptoms.
If you think that you may have one, please consult your doctor immediately. this is important to ensure that it does not spread and decrease the damage. You would need a urine examination and an xray of your lower abdomen before any other investigations are carried out.
The doctor may examine, run tests and then give antibiotics to help treat the disorder.
Hope this helped, let me know if you may need any more information.