@Hall0815,
Hall0815.
Is this the first time you have been "a thousand miles away" I am thinking not.
Your "preggy gf" ... it appears maybe having a child, her child, your child.
I'm not trying to sound rude here but, " My girlfriend is expecting a baby" it sounds as if she feels just reading your heading that you are not the one that she wants to be with in her life, yet, she's pregnant now and wants to be alone, and intends to keep the child.
You say you are staying away "for the baby's sake" which means, you are "ok" with her having the child. So, YES you have to pay financially, but you will be happy doing so, knowing you have bought a beautiful bundle of joy into this World, and from there you will have to work out rights to see your child, it's your child too, you have a right.
I would say, it's more to do with her not feeling the love and hasn't for a while, from you, as to why she doesn't want you on this part of the journey.
I am sorry that it's working out this way but it's life.