God promised Abraham a son,
A child is born only by natural law but God waited till the natural law in them was finished, both Abraham and Sarah were too old and unable to have a child naturally.
Then the law of the Spirit brought forth a son, the law of faith in God.

Is it possible that the delay you are experiencing is that you’re still walking in the natural law, your own ability, let go and step into the place where only God can bring it to pass in your life.