What do I say now?

One of the questions that keeps haunting my thoughts now, one that I have no idea how to answer and I dread the first time its asked....how many kids do you have?

How do I answer this now?  It seems like such a simple innocent question and yet it brings tears to my eyes just trying to figure out what I will say.  Do I say 2, a boy and a girl, and let Fiona get swept under the rug?  Do I say 2 living and 1 in heaven?  I can just imagine the silence and awkwardness that would follow, the slightly panicked look of the asker before they mumble something and look around for someone else to talk to.  Do I say 3, 2 girls and a boy and leave it at that unless they ask how old and then explain that one of my precious babies didn't make it out of the womb?  I have no idea.  I get nearly sick thinking about it, Steve doesn't know either and I know it makes him uncomfortable to talk about things like that but it's something we are going to have to figure out sooner than later.  He's back to work this week, my parents are getting the kids to and from school the next few days but eventually I'm going to be thrust back out into the real world and have to start talking to people again.  What do I say now?