As I said further down I'm an expert in food safety (or was) and (and this is totally sad) a Listeria expert. I usually point people in the direction of the Food Standards Agency website which has excellent advice on what not to eat whilst pregnant.
It's such a grey area though as different countries have different advice, in France I believe you are told to eat as much Brie as you can but to get rid of your cat for fear of toxoplasmosis, in another country it's no smoked salmon and prawns.
Some posters are genuinely frightened that they have harmed their baby by eating a prawn sarnie at lunchtime bless them. Can't we have a mix of advice and daft threads?