Everyone says "my baby"

So I announced my pregnancy to family this weekend, and one thing really annoyed me. My mom and his mom kept saying my baby this and my baby that. "Oh I can't wait to meet my baby!" "I wonder if my baby will be a boy or a girl?"
Sorry but this really annoyed me. Why do people say this? Pretty sure you weren't the one knocked up by my husband and who spent the last 2 months ralphing in the toilet.