Is it impermissible to use birth control pills without the husband's knowledge, especially when the fiancée wishes to postpone conception for one year after marriage to ensure the stability of their marital life, and so that the child does not become a victim of a potentially failed marriage?

If the suitor is a man of religion and good character, and istikharah (prayer for guidance) has been performed concerning him, then there is no justification for worry. Allah suffices for those who put their trust in Him. Procreation is one of the objectives of marriage, and neither spouse is permitted to prevent the other from it. Nor is it permissible for the wife to take anything that prevents pregnancy without her husband's permission. It is advised to strengthen one's connection with Allah through prayer, remembrance, supplication, attending gatherings of knowledge, and keeping the company of righteous women, and to avoid sins, so that anxiety may be dispelled.