Thank you, Holly. Tried to give you some reputation points for your wonderful and honest answer, but apparently I need to share it out a bit more first.

You are indeed very correct. Even if my sister doesn't have a bombshell for us, I think Christmas around them will just be too much to take, whether I get good news or bad from this cycle. I know I need to put myself first, but I guess I'm having trouble giving myself permission to do that. Will need a lot of discussion with DH, I simply do not want to spend the day around people that are clueless, tactless and completely insensitive to our situation. I suspect that I will end up having to write both families a long letter to explain why. It will make my mother sulk, but I think that it will have long-term benefits if I do. I just don't think I can take another phone call at the conclusion of a cycle, another question or comment blurted out in front of random extended family members who I really don't want to know the situation in full, another pregnancy/birth announcement dropped on me in a crowd with no preparation. I need something better/more/different from our families, but I can't see a way of telling them that right now.

I've really got myself in a pickle here.

BW