Pregnant Nurse in need of advice ASAP

Hello all nurses,
I started working as a Resident care coordinator over a month ago. Really love my job and I am already attached to the managment team and the staff there. My biggest issue right now is that I am pregnant 6months. Nobody knew about it when I got hired. Now I started to show and nobody ever asked too. I feel like telling my boss, but I just dont know how to proceed. Need help how to start the conversation. Dont want to let them down, especialy when I have to take my maternity leave in mid- april. Any advice to tell my team will be helpful!!
I have no children but I think it would be best if you approached them keeping a positive attittude... Maybe say something like I have a good news that I would like to share with you.. I am expecting a baby in April and I'm very excited... Maybe something like that.. It's a very excited time so be positive and don't let anyone make you feel bad about it.

i think it's better to tell them you're pregnant than to let them guess that you have developed ascites from some awful liver condition and didn't want to share. of course tell them, and be glad about it. besides, they'll throw you a great shower!