When it took us nearly 3 yrs to conceive #2, I would tell myself that I would want my friends to be happy for me when they found out if I was pg, so I was usually pretty good about it. I found it harder if family fell pg before us though.
You're probably right that they think that because you have your baby DS that you would be ok with it all and unless you (they) have had trouble conceiving it is hard to know what others have to go through.
Bookmarks