Thanks brickie and teenie!
I'm 12 weeks tomorrow, feels like a milestone. I've been telling a few more distant friends by text and email - funnily enough several of my old school friends are also expecting right now so we seem to be having a mini baby boom 
My commute, while long, is fairly simple as it's just one bus. I get the tube occasionally and do some travelling in London and around the south east and west for work. I'm not getting a baby on board badge as I just don't feel the need for one for me personally - I'm comfortable asking if I need a seat before I'm showing (or after!) and don't think a badge will make much difference to people's attention or niceness levels 
Re the bump, I don't have anything even approaching one yet. This is DC1 so not expecting to show for quite a while yet. My tummy's a bit more rounded and I'm definitely bloated a lot of the time but being quite petite I'm luckily getting away with it! Still, can't get into my trousers or jeans comfortably any more so changes are obviously afoot even if they're not noticeable...