If you get stopped and an officer suspects that you may be drunk and you refuse the BAC Breathalyzer test then you'll most certainly be arrested and taken to jail and they'll test your Blood Alcohol Concentration there instead.
Refusing the Breathalyzer test just means that you'll still have to take the Breathalyzer or a urine test and they'll make it harder on you.
If you know you're not that drunk then just take the breathalyzer test and make it easier on yourself and the officers.
Either way they'll get it done.