Can a uti cause nausea/ dizziness? what about a kidney infection? an abdominal ultrasound showed normal.

UTI: Utis really should not cause anything but bladder symptoms. If you are feeling worse after correct antibiotic course, see your pmd. This could mean your infection has ascended ( if you have stones), or bladder infection not sensitive to the antibiotic . Sometimes a peri-nephron abcess can form, but this is unlikely. See your pmd for exam and further testing if you still feel badly.