In Dutch oven or large saucepan, cook fettuccine to desired doneness as directed on package.
Meanwhile, spray large nonstick skillet with nonstick cooking spray. Heat over medium-high heat until hot. Add pork; cook and stir 3 to 5 minutes or until browned. Stir in carrots. Reduce heat to medium; cover and cook 1 minute. Stir in mushrooms. Cover; cook an additional 2 minutes.
In small bowl, combine milk, flour, salt and pepper; blend well. Add to pork mixture; cook and stir until thickened. Stir in vinegar.
Drain fettuccine; return to Dutch oven. Place over medium-low heat. Add pork mixture to fettuccine; toss to coat. If desired, garnish with fresh tarragon.