Annoyed with work

I have only told my managers that I'm expecting so far. I didn't want to tell my co-workers until I've at least shared the news with my extended family and close friends.

I think they're on to me, but I wish they wouldn't grill me. We had a work event on Saturday, on Friday one of them said "will you be drinking or do you have something to tell everyone?". I pretended not to hear her over the microwave in the kitchen. I didn't know what to say to that. They were making jokes about my 'pending mat leave' infront of a colleague from a different office in a meeting too.

After I left the event on Saturday my one co-worker that does know (needed help covering) told me that everyone was talking about my belly. It's honestly barely there! It's only noticeable because I normally have a very flat stomach. What if I just gained weight? My sister gained weight on fertility medication and hated when people kept assuming it was pregnancy.

Sorry for the rant, but I want to be able to share the news when I'm happy to and ready. Not because I feel backed into a corner. I might be super sensitive to it because of my sister's story of her difficulty concieving, but I feel like people need to mind their own business.