I liked this Prayer for an Expectant Mother I found in a redemptorist prayer booklet I got at a novena this year:
Dear kind Father, giver of life, lover of humanity,
I bless you for sharing with us the joy of creating new life.
I thank you for the frail but eager human life that is blossoming in my womb,
Fill me with your peace and love, so that my baby may feel only peace and security
During these months of closeness. Give me courage and joy and strength so that every beat of my hear may speak welcome and delight to this vulnerable little person who is bone of my bone and flesh of my flesh.
Keep us both safe in your love now and at the moment of birth, so that my child may be a healthy child who will live to love and serve you through a long life.
Jesus, Mary and Joseph be close to me and my child.
Angels of God, watch over us and keep us safe from all harm.
Amen.
I hope you like this prayer

. Also, novenas and prayers to St. Gerard Majella are used a lot here in Ireland for expectant mothers.
Wishing you every blessing as you carry your little baby. Will remember you in my prayers today.
God bless.