how to announce to friends with infertility

I have a dear co worker who struggled with infertility and ended up not having childten and I also have a friend who has been trying for a year with her boyfriend and no luck yet. I am 5 weeks 3 days and I'm seeing that friend tomorrow. I want to tell her but I want to obviously be respectful and delicate about it. If you were one of these two women how would you want to hear that a friend is pregnant? Once they know is it okay to talk about or should I avoid the subject unless they bring it up? I just love them and don't want to upset them.