Goodluck with it all, i hope they show you lots of joy for your exciting news and that everything goes smoothly for you.

Maybe if they live close enough you can organise a dinner, maybe say to them are you ready to have a baby around? I'm xxx weeks.
Even if you want it can't hurt to wait until 12wks and you can pass over the scan pic, if they ask why you waited so long you can say you just wanted to be sure before getting everyones hopes up again?

Whatever happens please remember every baby is a miracle and even if other people can't show the joy and respect that you hope for it doesn't mean it's any less special to you!