Quoting tatesmommy09:" Unless you are married, a father has no rights to his child until he goes to court and establishes paternity. ... [snip!] ... curretly in this situation. My neices mom can take my neice anytime she wants because he still has not established paternity."
I know this is 3 hours old, but that actually is not true.
In michigan, and most states if there is no court custody order both parents have 50/50 custody and can just take the child and not give them back until it IS set up by the court.
OP, everyone else is right, you need to file for custody and support as soon as baby is born. Good luck!