You are 18 and your girlfriend is 16 and pregnant what rights do you have?
SHAME ON YOU ,
Reposting my legally correct answer, which someone erased for no valid reason.
If you're in the US... At this point you have no rights. Once the baby is born, you have the right to petition the court to establish paternity (unless you and Mom agree to voluntarily establish it) and to petition for custody/visitation. Of course, you also have the responsibility of paying child support. To be clear--your rights extend *only* to the child, not to the child's mother. So, for example, if her parents forbid you from seeing her, they have the legal right to do that. And they can get a restraining order against you (so if you contact her against their wishes you'll go to jail). My advice--don't p*ss her parents off.