You're not religious, OP so you have no reason to believe that having a baby is a miracle.
I do think miracle babies (after loss, or infertility) are amazing, but the phrase in general irks me because it makes people like my lovely beautiful friend who can't have children believe her life will never be complete.
I am going to be hard here. Your dad died because he had a cancer that made his body stop working. He would have died whether you had a baby or not. I imagine your father just wanted you to be happy, and that doesn't mean "with" baby.
I believe in karma myself, but karma is all about intentions. Good intentions, as opposed to good actions.
And for what its worth, if there is a god, we have free will.
And as cold as this may sound, ain't no-one going to hell for having an abortion, otherwise the majority of women would be there. You are far from alone.