Hello and welcome to HCM, Thank you for your query. As you are aware of the symptoms of a UTI, I wouldn t have to run them through you. What we need to know is whether you were treated for the UTI (either self treated as this condition is common to you, or by your doctor), if so then there could be a chance that the test results return negative. If you also see spotting or blood in the urine, along with lower back pain, we should rule out all causes of a UTI. UTI s are not supposed to be common, and if they do recur, we should consider a more elaborate diagnosis. Many different conditions cause UTI s and any such condition could be causing a UTI, in you. My advise would be to conduct an ultrasound of abdomen and pelvis, to rule out causes like stones, tumors, etc. In the mean time, please drink as much fluids as possible, even if this results in frequent urination. I hope I have succeeded in answering your questions, you could write back to us anytime for further clarifications. Best wishes.