For under $200 USD's you can buy yourself a very good personal breathalyser and thus take any / all anxiety out of the equation!
Professional Breathalyzers - AlcoScan Premium AL7000 Breathalyzer - Breathalyzer
Which Breathalyser Works Best? AL7000 Gets Top Rating!
For those occasional days when you might be feeling a bit 'overindulged' and / or 'anxious' before you go to work, blow in to your personal breath tester and if doesn't immediately read zero then call-in sick... aside from going teetotal, what could be simpler?!