I'm going to weigh in here since I went through this and am well over 10 years into it.
I got my girlfriend pregnant 2-3 weeks before I broke up with her and moved back to the USA from Japan. The end was coming, we were not in love and since it was time for me to go back to the USA we were not going to pursue a long distance relationship.
She insisted on not having an abortion and I begged her to since I was in no financial place to take care of a baby, having just returned to the USA from school in Japan. She was not happy with me for asking her to abort. We had some serious fights over it. She refused to listen to my reasons - and still expected me to marry her.
So I married her. Got her a visa and she moved here. A woman I had dated for all of three months, and had a significant age gap with. (10 years my senior - I 23 her 33 at that time)
Our relationship has been garbage for all 10 years, but I have done my best to be a good father. It has been the literal definition of a sexless marriage. Neither one of us has ever forgiven the other - and I have even stayed with her through a cancer battle.
She took my youth and dreams and goals, I asked her to give up the one thing she ever wanted in life.
I am going to drop the divorce bomba on her very soon. I can't do it anymore. I feel like 10 years of my life were wasted.
So long story short, stand your ground. Get her to have the abortion. If she won't man up and be a father but don't marry her. She will never forgive you for asking her to abort if she wants to keep it.
Thank you for sharing your story. I went through something similar as well 13 years ago. I was having a casual relationship with a woman, which wasn't working out. She got pregnant, and announced it to her entire family before telling me. I waited two days, shell-shocked, and then asked her to get an abortion. She refused and resented me every day for it. Then I made the worst mistake, same as you- I married her, to be there for my son. After 8 loveless, unhappy years and two more children (one of which she secretly stopped taking birth control to get pregnant), I divorced her. Now, 4 years later, I have full custody of our oldest, and we share equal custody of our other two children, perhaps soon to be with me primarily as well. I love my children very much, and I wouldn't be where I am today without them, but it was a painful and expensive path.
I agree with you 100%. You do have to stand your ground with regards to your position on abortion. If she decides to have the child, you must be a father. Fight for equal time and equal legal rights. Sacrifice towards that goal. Understand your rights. Don't just be a support check. Children need a father more than they need money.