if you're keeping to induction levels.

From the Atkins website:
(Under Acceptable Beverages)

In addition to at least 64 oz. water per day you can have "Cream, heavy or light (limit to two to three tablespoons a day; note carbohydrate content)".

As others have already said, cheese in excess of 4 oz. can stall some people. Velveeta is nice, but it is kinda loaded up on carbs. A way to maybe get cheddar and other cheeses to melt 'nicer', is to maybe add a touch of heavy cream to enhance the smoothness.

Again, Fitday may help a lot in figuring out your caloric intake and percentages.

Good luck!
Nikki