...sis, I'm so sorry you have to experience this, especially during a time when you have your precious little one in your womb.
The one thing that I can say to you is for you to trust the Father and really believe that He has this under control. It might be too much for your husband right now...new marriage, new baby...responsibilities for a man sometimes can be overwhelming, and their first thought is to leave. Trust...he is thinking about you and the baby and probably is too ashamed to come home to you, after he left you for so long.
It will be hard, but think about the baby and try to remain at peace. Peace in your soul and your spirit. Have as much quiet time with the Lord as possible and the one thing I ask you to do is not to listen to every person that has something to say about/against your husband....just because they have an opinion.....
You must pray and trust that your husband will reconsider his actions and come to his senses. Pray that God will bring the right people into his path that would speak life over him and his marriage and for him to do what's right.
I will be praying for you....