Bring a large pot of salted water to a boil and cook the whole wheat spaghetti according to package directions until al dente.
While the pasta cooks, spiralize the zucchini into thin ribbons and set aside.
In a small bowl, whisk together the egg and grated parmesan cheese until well combined.
In a large skillet over medium heat, sauté the diced pancetta until it becomes crispy and the fat has rendered.
Add the diced chicken breast and minced garlic to the skillet, seasoning with sea salt and black pepper, and cook until the chicken is golden and cooked through.
Just before the pasta is finished, add the zucchini ribbons to the boiling water for 30 seconds to soften slightly.
Reserve 0.25 cup of the starchy pasta water, then drain the spaghetti and zucchini.
Turn off the heat in the skillet and add the pasta and zucchini, tossing them thoroughly with the chicken and pancetta.
Slowly pour in the egg and cheese mixture while tossing constantly, adding a splash of reserved pasta water as needed to create a silky, creamy sauce.