I have done blood and urine test . in my blood biochemistry test my glucose was 125 mg/dl and i was fating for about 5 hours also in urine test, i had ketones . i am on a low carb diet for about a week . my ph is normal. is this pre diabetes?

Normal fasting blood glucose level is between 80-100mg/dl. But, a single high fasting glucose is not an accurate measure of prediabetes or diabetes. You Dr should follow up with a HgA1C which measures your blood glucose over time. HgA1C below 5.7% indicates normal blood glucose, Between 5.7% and 6.4% indicates prediabetes, and Over 6.4% indicates Diabetes.

You should re do the test and have your blood tested at an accredited laboratory. Results from glucometer are not adequate for a diagnosis. Having said that, if two correctly done tests show fasting plasma glucose level between 110 and 126, that would indicate pre-diabetes. Visit this site for info: https://www.diabetes.org/a1c/diagnosis