My Doctor Prescribed Antibiotics (Bactrim) For UTI 10 Days Every

My doctor prescribed antibiotics (Bactrim) for UTI 10 days every 12 hours. I am almost through the pills and don't feel any different. I have sharp pains in my abdomen that comes and goes and is sporadic. Sometimes my upper back feels like its burning or muscles drawing up. My pulse rate is 106 sometimes I have high blood pressure but haven't for a couple of days. I would like to know what would cause this and should I go to the hospital?
Thanks