Irritated

I am so irritated right now! My brother-in-law P just announced that his wife N is pregnant. He told G and me a couple of weeks ago (that story is a separate post though) so it wasn't a surprise. However, they way he wrote it is what really got to me. He knows about our situation. He knows that we are very likely to never have our own biological children. He seemed very supportive at the time.
Today, I got on Facebook and saw the ultrasound picture that he posted. Along with it he wrote, "P- 1 Natural Selection- 0." I know to most people this doesn't sound like it would be such a big deal, but it actually hurt my heart. I won't ever say anything so unless he reads this, he won't ever know. It just doesn't seem worth it to bring it up. It's not going to change anything. The only thing he could say is, "I wasn't thinking," and "I'm sorry." I don't need an apology. I just need people who know to be more sensitive. I know it won't happen though.
Fertile people just don't understand what it's like to be told you might never have children. No one can understand what it's like to go through infertility unless they themselves are going through it. I guess I just need to develop a thicker skin and spend less time on Facebook.
How do you deal with pregnancy announcements? What do you do when someone says or does something insensitively?