You should consult a legal authority who understands these matters in your jurisdiction. For all we know, you live in Saudi Arabia.
My common sense answer is that you have no rights to the unborn child whatsoever. You have no say over whether she carries it to term, what name to give it, how to raise it, to have your name on the birth register, or to inform you of her whereabouts.
In other words you are a in a position to demand nothing.
But I feel that you are certainly able to make a polite and well reasoned argument about why you should be allowed to help with the raising of your own offspring. What have YOU done? Have you offered to help financially? Are you a good role model for a child? Would you be someone that can be relied upon to help with the infinity of chores that come with parenting?
I'm guessing by her reaction that she doesn't think highly of your abilities. Whether or not that is fair, you have an opportunity to convince her otherwise.
Good luck dude