hun i know exactly how you feel.
i don't have any kids but have been trying for 3yrs now. i dread those announcements. like you i get teary just thinking about it.
my sil announced it to everyone for the last one. she knew how long i had been trying. i was really upset and had to suck it up until i got home.
i told her another day that she should have told me separately so that i had private time to process it. i hope she has enough respect for me to do this next time.

hun. its hard.