If you have more than two kids are you overpopulating the planet?

I was thinking about it and if you have two kids then that replaces you and your spouse. But if you have more than that you are contributing to overpopulation. Do you think parents who have more than two kids are selfishly contributing to the earths demise? I think the max occupancy for earth is about 10 Billion, right now were at about 6.5 Billion. Population doubles every 35 years, i think it may happen in our lifetimes. What are your thoughts?