(This is my view of what I think Calpurnia might have been thinking the day of the games - view last post for more info on the games)
Calpurnia: I don't want to get out of bed today, I like to see the games but I can bear no children and I know that Caesar is going to ask Antony to run by and strike me with his thong which is embarrassing and also quite painful. Does everyone really have to know that I can't have kids? Its very sad to me in the first place and having everyone know and wonder about it only makes it worse. But who knows? Maybe it will work, this whole thong thing, and I'll bear Caesar a son. Then, I could be happy. To know that my lord will have an heir and to have a child all of my own. Then, only then, can I be truly happy to go out in public and be proud of who I am.