It's getting more obvious

On Thursday 21/Aug, 4 of my colleagues asked me if I'm preggie in one same morning.
The first who asked, is my group's colleague who asked while we were walking back together from breakfast. Question : In cantonese "ah... lei yau cho hai mm hai?"
Coming back to the office, I handed over my Medical Leave Cert to my dept secretary. Over the tall dividing partition, she asked me, in Malay : "Amoi, you ada orang dalam you ke?"
Then, while walking out from my office, met two of my other colleagues, both guys walking on the opposite direction, one of them was looking at me and tummy and asked, in cantonese "hmm, hoi chi dai cho ke?" The colleague next to him continued by saying something like "I also notice it, just that I did not wanna ask".

So, well.... BB / tummy speaks for herself. :) But I guess it would be better for me to break the news to my lady boss rather than she hearing from others. But how to tell ? No opportunity to approach her for a business talk, not to mention now, a casual talk.