When I was pregnant with DD1 I lived in Hertfordshire and lots of times people offered me their seat when I started getting bigger. I now live in London and no one has ever offered me a seat.
I was always taught to get up for older people and if I saw a pregnant woman would do so too, its just the way I thought the world was. Here I see lots of young people sitting at the front of the bus who don't even move for old people or people who obviously have trouble standing, let alone pregnant women.
I'm not feeling sorry for myself (although it is a pain in the bum being pregnant on a busy bus with people sqeezing between your bump!) but it makes me wonder sometimes if I still live in the dark ages!