I have been in this position. In college, I got my girlfriend pregnant despite using birth control. What I wanted was irrelevant. When she told me she was pregnant, I told her that I would support her in whatever she wanted to do. That's it. I didn't mention abortion because I didn't want to pressure her in any way. Fortunately she chose to abort, which I paid for since I was working and she wasn't. But if she'd said she wanted to keep the baby, I would have helped her raise it and probably would have married her.
Since the fetus is inside of the woman's body, the man should have no say in what happens to it. It is entirely up to the woman, and the man's job is to support her 100% in whatever she wants. If this is a problem for you, don't dip your wick because you lose control once your sperm cells leave your penis.
