Bring a large pot of salted water to a boil. Add the fettuccine and cook according to the package instructions until al dente. Reserve 1 cup of pasta water, then drain the pasta and set aside.
In a large skillet over medium heat, add the olive oil. Once hot, add the minced garlic and sauté for about 1 minute until fragrant.
Add the shrimp to the skillet and season with salt, black pepper, and red pepper flakes (if using). Cook the shrimp for about 3-4 minutes until they turn pink and opaque. Remove the shrimp from the skillet and set aside.
In the same skillet, pour in the heavy cream and reduce the heat to low. Stir in the grated Parmesan cheese until melted and well combined. If the sauce is too thick, gradually add some reserved pasta water until the desired consistency is reached.
Add the cherry tomatoes to the sauce and stir until heated through, about 2 minutes. Return the cooked shrimp to the skillet and combine with the sauce.
Gently toss the cooked fettuccine in the skillet with the creamy shrimp sauce until well coated.
Garnish with freshly chopped parsley and serve hot.