Has a kub xray today for kidney stone it was normal does that mean kidney stone passed?

Not necessarily. Kidney stones are quite tiny despite severe pain when they move. A KUB will miss tiny stones and nonopaque stones like uric acid or cystine stones. An ultrasound or renal stone CT scan would be more apt to detect a stone, but the CT scan is best. Drink lots of fluids& strain all your urine with a handkerchief to look for a passed stone. Bring it to the lab for analysis.

If the kidney stone was visible to KUB earlier and is not visible now, then it likely passed. However a first KUB not showing a stone does not mean that a stone that you may have had has passed.