I have had urin test, cat scan, and blood work and nothing shows anything. i feel like i have a uti. what can this be? they put me on antibiotics anyway

Need more info: You give no info on your symptoms, the results of tests which you say are normal, and have not been able to examine you. The doctors seeing you are in a far better position to speculate on the cause of your illness. Discuss this with them, and if necessary get a second opinion from somebody you can see face to face. Good luck and hope you get better soon.