Ruth - firstly, you are not being oversensitive. It is a tough road ttc with Infertility issues etc.... Infertility is still a slightly taboo subject (unless you are on forums like this one or talking to other going through it) and also people who don't experience infertility don't really know what it is like. (Exactly the same when people experience loss of a child & other people haven't) - they just don't know what to do or say.
IMO & experience the less you tell people the less they know what is actually going on and say things that necessarily may not mean to be insensitive but do come accross that way to people like us b/c of all the emotional & physical experiences we are going through. All my close friends know we are off to see if fs next month & it makes it easier for them & me b/c they are more sensitive even if some of them haven't been through it. They tend to tread around me a little bit & realise when I do want to talk about it & when I don't. The ones that don't know go ahead & announce pgs, talk about how hard it is ttc (like for 3 months) etc.... I have only just learnt to open up more & geez it has made things much more easier for me.

The other thing about your friends - they want to share their exciting news with you, their friend who they assume would be just as happy as them about their news..... and whilst you are in some way, there is always that tings of sadness, jealousy, whatever etc....

Perhaps you need to voice more about how hard this 'journey' is for you so they can understand and be more intune to how you are feeling. - just a thought.