no clue why he would do this..

A little background...this baby wasn't planned. SO has come around to it and now says he's excited. He was on the phone for an hour last night with his ex wife discussing mostly their sons. He broke the news to her about the baby like this, word for word. "She's pregnant...it wasn't planned. Well wasn't planned this early I guess." She says congrats to him, then he says thankyou. All of this was said in a tone that you'd think he was telling her someone died... We agreed long ago that it was no one's business if it was planned or not and we agreed to act happy about it. Honestly I'm quite upset and he just doesn't get it...at all. Am I in the wrong?