Cook pasta in boiling water 6 minutes, omitting salt and fat. Add peas, and cook 2 minutes; drain. Heat oil in a medium nonstick skillet over medium-high heat. Add shrimp, oregano, salt, pepper, and garlic; sauté 3 minutes or until shrimp are done. Combine pasta mixture, shrimp mixture, and remaining ingredients in a large bowl; toss well.