it is a recurrent Urinary tract infection
which probably in your case comes as petechial rash
followed by haematuria.Since blood tests are normal only two things remain.One is please get urine culture
with sensitivity done to rule out any organism
& get treated accordingly .Secondly also note that being a female was this episode close to the date of menses to rule out if the haematuria was also associated with some blood mixed coming from uterus.