I’m afraid that whatever you decide, one of you may well end up resenting the other.
If you have an abortion and stay together and have another child later, you may resent that you didn’t keep your first child.
If you have an abortion and don’t stay together but either of you doesn’t have any more children, you may be heartbroken that you didn’t keep this one, your only chance.
If you keep the child and he buggers off, you will resent each other. You because you are doing it alone and him because he has to pay ( usually a tiny amount but many men believe they shouldn’t have to support their own kids).
If you have an abortion that you don’t want to ‘keep your man’, he will probably leave you anyway. Or you could end up hating him for what he made you do.
Etc etc
I’m afraid there are no easy answers to an unwanted pregnancy, especially for the woman.
Whatever happens you will probably feel sad, angry and guilty and your body and mind will be affected by the pregnancy, however it ends.
The odds of your relationship surviving this are slim , which is why most people on MN will tell you to do what is right for you and your potential child, not for a man who will probably not stay around .
Sorry if that sounds harsh but that’s the reality.