Should a couple marry with the plan to use NFP to temporarily avoid having a child? It seems to me that the couple should wait to marry until the situation is more favorable to children.
If the couple has just reason to avoid pregnancy, it is not wrong for them to postpone their family. This is true even if they are not yet married and are planning to marry. It is true that such a couple can have selfish reasons for avoiding pregnancy, but it is their selfishness that is the problem and not the use of NFP.
God, Sex, and Babies by Christopher West