I'm pregnant with twins and get the same response - 'you are so small'. I am almost 24 weeks and really only 'popped' about a week ago. But I went out sideways instead and certainly have put on a lot of weight, its just I haven't gone out in front yet which is what everyone seems to look for. So I think it just depends on body shape, diet, number of pregnancies etc etc. Everyone is different but I reckon enjoy being smaller while it lasts cause soon it will be very big and uncomfortable and we will be wishing to go back to smaller belly :-)