How often you test your blood sugar depends on which type of diabetes you have, your blood sugar range and what kind of treatment your doctor prescribes for you. Your doctor will provide guidance on how often you should test it. If you have type 2 diabetes and take insulin to manage it, your doctor may suggest you test your blood sugar two or more times per day, usually before meals and sometimes before you go to bed. If you use noninsulin medications or manage your type 2 diabetes with diet and exercise, you may not need to test it as often.

Source: http://www.mayoclinic.org