NFP is not an illusion of ultimate control, which is what you have in the case of condoms or birth control pills & patches, morning-after pills, IUD’s, and by extension of these methods, abortion. It’s not a permanent closing of the body to the possibility of life, as in the case of elective sterilization. It’s an acceptance that the sexual act is a sacred gift of giving your body to your spouse, which could create a new child who is “fearfully & wonderfully made” by God himself. To be a willing participant in this way echoes Mary’s fiat: May it be done to me according to your word. It takes trust to do this, but your Heavenly Father is certainly worthy of this trust. I hope you will consider taking His hand and allowing Him to guide your family.