My husband didn't tell anyone I'm pregnant, why?

I have 2 kids from my previous relationship. 2 kids is all I wanted to have. However, I married a man without kids and his dream was to be a father. 
So I promise him that I will have another child. We have been married for almost 2 years. I'm almost 4 months pregnant and he has not told anyone. 
His family from his mother side didn't approve of our relationship because they didn't like the fact that I have 2 children already. Specifically his mother criticized me the most but she had 3 children from 2 different baby fathers who didn't help her when she got married the last time. 
My kids father supports my kids, takes them on vacation every year, takes them almost every weekend and loves my kids with his heart. 
Why if I'm sacrificing so much my husband seems not to be excited? I'm giving him what he wanted.