Ok, people won't usually say anything about two topics:
1. People who they think are pregnant. and
2. People who are losing weight.
These are just sensitive topics that people are very worried about offending people about. So, I wouldn't read too much into the fact that people aren't saying anything--they are probably noticing but don't want to say anything because they don't know if you want to talk about it or not. My SIL brought my weight-loss up the other day in front of my whole family and I wanted to smack the daylights out of her--of course she was completely offensive and condescending, perhaps if she was nice about it I would've reacted differently. She's crazy.
Anyway, you know your progress and your success and we know of your progress and success. Be strong and confident and try not to let others control your happiness. :-)

You rock!