Hmm. Maybe he's finding it hard to adjust to your new body? Or maybe it's the thought that his baby is in there thats putting him off? I don't know, but what he said to you sounds really nasty and he sounds like a twat!! I would KILL my oh if he said that. How can he expect you to go straight back to normal after giving birth to his child?? He should love u for who you are and not care what your body looks like.
I love the name sienna, i dont know any other ways of spelling it, i think that way is nice! x