I also feel awful when my jealousy rears its ugly head, too. I don't doubt that you really are happy for them. I'm truly happy for my pregnant friends too. I just wish I were joining them, and well, it stings. For me, it's more that their annoucement reminds me that once again, I'm not pregnant, and someone else is. Whenever I hear a pregnancy annoucement, it starts me down that road again... why was it so easy the first time? Why, oh why can't I get pregnant now? What am I doing wrong? Will I ever see those two lines again? Am I a crappy mother and nature is making sure I don't screw up another child, etc. All kinds of nonsense goes through my mind upon hearing a pregnancy announcement, and I so wish it didn't. I don't want to be the girl my friends hide it from, becuase they think (or maybe even know) I can't handle hearing it. But some days, I really can't, and I think it's really, truly sad.
Honestly, I don't know how to let it go, either.