If my blood sugar is 150 after meal, could i be diabetic?

No: If it's 150 right after your meal, then it's normal. If it's 150 2 hours after your meal, then you might have pre-diabetes. The glucometer is not designed to diagnose diabetes. You need a blood draw to diagnose diabetes. Very easily done.

Unknown: A 150 mg/dl blood sugar after a meal could be ok if it was less than 2 hours after a meal and went below 140 by the time 2 hours passed. This, however, is based on lab glucose values. Home glucometers can be off by a significant amount so a 150 could be either higher or lower. If you suspect you are at risk for diabetes please see your doctor.