I think it could be possible that I have uti, I have peed out blood clots since yesterday morning, but as I arrived at the doctor's today I had to give a urine sample, this time it did not burn and they're weren't any clots, but there was blood mixed in my urine.the doctor gave me medication for uti.I am 13 years old and I'm am worried.I am concerned if there is more to it and if it is not uti.