The symptoms you have described may be due to stone causing obstruction in the urinary tract
.Indiscriminate use of anti-microbials is not warranted.
I suggest you get USG kidneys & bladder done.
Ensure 3-3.5 litres of liquid intake daily after obstruction has been ruled out/tackled.Once this is done then there is nothing to worry about.
Presence of pus cells in the urine in the presence of stones is a common finding & does not always suggest infection