I've been on klonpin for almost 3 years my dr just changed it to ativan (lorazepam) 6 mg will i go threw withdrawal with this change?

Can't be sure: You would have to know the dosage of each medication, how often the meds were taken per day, as well as when they are taken in order to anticipate if withdrawal symptoms would be expected to occur. Even then you couldn't be certain that withdrawal symptoms would occur. Discuss with your doctor why you are taking the meds and what is the overall plan.