Second thoughts

My relationship is falling apart. My fiancé is growing more distant... And the only real thing that has changed in out relationship is that im on bed rest so things have been a little harder.. And of course that there is a baby on the way. My second child, his first.  We've known one another for years and we planned this child and he proposed. We are supposed to marry this fall. Little things have been happening that make me feel something is bothering him. I assumed it was nerves but he validated today that we need to talk and he wants to figure some things out about us.  Meaning when he gets home he could very possibly be leaving the family he made with me. I asked him, out of fear, if he thought about leaving and if it was that. He told me just that he wants and needs to talk. I feel like I am preparing myself for the worst. For my oldest son losing a dad he never had before hand .... And they bonded and grew so close and he willingly and wanted to become his father. I'm due to have his chikd in just a few weeks.... I feel like a monster but I can't help but sit here and not want this child anymore.   If he abandons us and everything we built together... I am left with two children... Alone... And I would have to continue to speak to him and see him regularly because of the child. I know I will keep this child. I know myself. But in the back of my mind I wish it could be undone. So all I will be left with is a shattered heart. Am I a horrible person because of this? ..... I feel so lost and afraid and suddenly alone.