hello there! rigors and chill, urgency and freequency mild blood makes the odds for uti greater. now the history of renal calculi is also something not to be ignored. remember painful hematuria( blood in urine) is always a stone. that pain usually radiates from lower back and shifts to same side of the groin. it is usually sudden in onset and very severe only opiods and antispasmodics can relieve. any ways one step to diagnose which is it is an ultrasound abdomen and pelvis and simple urine routine exam. first do the later, if uti is ruled out its definetly a stone, mean while treat the symptoms, get some anti spasmodic like spasfon get oral tamadol and drink alot of water as it will push the stone and help it pass if it is up to 5 cm. rest i wish you good luck if uti comes out then use ciprofloxacin 500 mg for 5 days above treatment and hygiene care by biomousse gel rinsing it like a shampoo for 5 mins at least. during washing the groin are after pee and defecation, use the movement of your hand in forward to backl ward direction ( that is from urethra to anal direction)and then lift hand dont come back rubbing and then the same., so this one way rubbing will help avoid chances of uti to. this tip is for women and it works like charm as their urethra is very short. too bad this quey status doesnt show the gender of inquirer unless you answer it, good luck any ways. hope i was help ful regards