Sick of people saying I'm too big

I'm 25 weeks pregnant. I went back to work at my old workplace about 4 weeks ago. Because everyone knows me they think they have a right to comment on how big I am!!! When I tell them I have 15 weeks left I get 'you're massive!' 
'Are you sure there's just one in there?!'
 'You look about 8 months!' 
'No way are you going to make it full term!' 
It's really affecting how I feel about my pregnancy. I was around 220lbs when I got pregnant, and have only put on 3lbs since!! I'm carrying mostly on my belly as I've lost weight every where else. 
Now I sort of feel ashamed of my bump and try to cover it up to stop the comments. 
Anyone else had this?!