Well I reckon I win this thread - I bought a Polarn O Pyret babygro before we even started TTC. 
Could well have been a curse, but it was just so ridiculously apt for us and the last one in stock online in the sale that I just thought fuck it. Luckily we conceived cycle #3. I'm 12+2 and still haven't shown it to DH!
Apart from that though, I'm not fussed about buying anything else yet. We're not even going to bother to decorate the spare room or buy any furniture for it as the baby won't even be in there till this time next year.