No, God was always the Holy Trinity. The Fathers and the Ecumenical Councils speak of the Persons of the Trinity being co-eternal, of the begottenness of the Son and procession of the Spirit from the Father as being eternal.
You are skating very close to the formula of the condemned heretic Arius, 'there was when the Son was not'.
Nothing ever changes with you guys.
You are, well, boring...
Don't you find the idea of a changeable God fresh, exciting, and new?
The Nicene creed from 325, 381 holds that the incarnation was before creation. Of course co-eternal is true from that point on. the procession of the Holy spirit from the father was always true. The Father's person is the Holy Spirit.