I am a strong believer that Yahweh has control over everything. He is supreme in all matters so whatever exists and whatever happens has a place in his plan. Certainly some things are his direct will and others are his permissible will but it is Yahweh who knows all and is all powerful so nothing is by accident. I believe he also has authority and control over the womb. The "fly in the ointment" is that he has given us free will and if we choose to take control he allows us, no matter the results.
Many people struggle with this because of the various difficulties they have faced. What do you say to a woman who is desperate to have a child and cannot conceive? It seems like a platitude to say that Yahweh is in charge, even when it is the truth. What each of us have to struggle with and eventually surrender to is that we must let go of our will and desires and seek Father's will and desire. It is important that we acknowledge and accept that he has purpose for everything he does and allows in our lives. We have many examples in the Word as well as testimonies of believers that bring this reality into focus.
I often think of Hannah, Samuel's mom from 1 Samuel 1. She was desperate for a child, even though her husband loved her dearly without one. However, Yahweh resisted her. In verse five of this chapter it says "although the Lord had closed her womb". It has always been his desire for us to be fruitful but in this and many other cases he resisted the desire of the woman by closing her womb. But imagine for an instant if he had not done so.
It was because he resisted Hannah that she earnestly sought him. It was because he resisted her that she offered her first born to the priesthood. She became completely surrendered to Yahweh and it resulted in the great priest/prophet/judge Samuel. We may not always appreciate it in the moment but there are times that Yahweh resists us to provoke us to earnestly seek him, to open us to his will, and so we can see the doors he has opened.
When I got married at the age of 22, children were not really on my mind but it was the great desire of my wife. She figured she would get pregnant immediately and start on our family. For six years we tried but her womb was closed. In those six years we prayed, called out to Yahweh but he did not respond and the doctors could not find a cause. But the Lord opened a door and provided our first child through adoption and what an incredible son he has grown into. The Lord has his hand on him and we have not yet seen what will result but we have no doubt he gave him to us for a purpose and it would not have happened if the Lord had not resisted us.
As a foot note, it was when my wife completely surrendered herself and told the Lord she would be satisfied with his will for our family, whether one child or multiple, that her womb was opened and never shut again.
Christians have a struggle over control and Father's will. Jesus set for us an example of what it is to live a totally surrendered life, even one that includes difficult moments. There would have been no resurrection without the cross. There are no victories without battles. If the Lord is resisting you on a matter that you know to be his will, earnestly seek, trust and surrender to him and see what he has been wanting to produce through you. Give him back the control over everything in your life.