Type 1 Diabetes and kidney infections

I am a 25 year old female with Type 1 Diabetes which I have had for 21 years. For the past year and a half I have suffered from kidney infections, at least 1 a month and I had never suffered from any prior to this. I have had a CT Scan, ultrasound and cystoscopy done over a year ago but nothing was found. All they found was the infection I had was uncommon and my right kidney was larger but was nothing to worry about. It is my right kidney that is always sore and I feel it niggles me constantly. My infections have varied between feeling generally unwell to full blown fever, sickness and leg pain. I was put on a course of anti-boitics for 2 months but I am still getting infections and my right kidney always seems to be sore. I was also tested for kidney disease over a year ago but again this was not found. I am worried it could be the case or that something is there but not found. Is there anything else it could be or am I just really prone to infection?