Low carb should never mean 'no carb'. 'Pigging out' is never a good concept to get into. If you provide the body with sufficient proteins, carbs, vitamins and minerals on a daily basis, then you will do much better than undertaking any form of nutritional deprivation.
Beef and spinach tortellini doesnt sound nutritionaly terrible. The beef will be relatively low quality as it will be minced, and so high in saturated fat, so go easy with the accompanying sauces (have it with a tomatoe based sauce instead of a cream based one), and eat it in sensible portions, and there is no reason why it couldnt become a regular part of your weekly meal plan.
If you want to look at balancing carb intake, do it through the day, not day by day. This means scaling down the amount of carbs you take in as the day progresses, starting with a carb rich breakfast, and ending with a low carb evening meal. 'Carb days' and 'non carb' days are just a way of screwing up the consistency in your nutritional balance.