how to tell my co-workers??

I work as an occupational therapy practitioner in a preschool and I'm friendly with mostly everyone (teachers and assistants and other therapists) but not very close except for a few, and I actually really dislike a few of the women there lol. not sure how or when to reveal.

I'm 6w3d with #2 and already bloated but unsure if ill be able to make it another 6 weeks (until past the "danger point") of growing without showing everyone. I want to hide it until its more real and then need a way to tell a bunch of women.