This is one of the hardest aspects of grief, the loss of innocence. Having had several pregnancy losses, I find it very difficult to endure "normal" things like a coworker gleefully announcing an early pregnancy. My first thought is "Yes, but there are no guarantees" and then feeling bad, because it's something you shouldn't even think much less say. And I can remember being that joyful, that ignorant... and I miss it. And then of course realizing that nothing bad will probably happen for them, which brings up all kinds of self-pity about one's own situation, and a touch of jealousy. They will be fine... why not me?
I am sorry for all you have been through. Your words are important for others to hear.