I totally understand where you are coming from also, and have had similar experiences with people announcing pregnancies and not seeming to consider for a moment, that it might be hard for me; or going on and on about their pregnancy to me etc. I truly think people get so caught up in being pregnant that they forget to be sensitive, or maybe they just dont realise how hard it is for people struggling to conceive.
sorry you are having a tough time...at least here we all understand