How do I get physical custody of unborn baby

[acieniuch]

I am married with 4 stepdaughters and my first child is due in October. My wife has recently left me and moved back to California, I live in Illinois. What rights do I have to get physical custody of my unborn child? I still love my wife and wish none of this had to happen, but I don't believe its fair to not be able to see my child and only write a paycheck. Please email me back with any information.