I am in the same boat, my personal beleifs are against it but I cannot tell anyone how to live their life, just urge them to the best of their ability to not terminate the pregnancy.
My daughter was not a planned pregnancy, when I did not put a ring on her mother's finger she threatened to terminate the pregnancy, then she told me she even stopped by planned parenthood for more information.
Regardless it was the right move to talk her out of it, even though we're not together and have been fighting over that little girl for the past two years in court, every day I have her things are great and every day she's not around I miss her immensely.
Your decision is your own but do what you can to make peace with yourself, that is something I've never been able to do.