SO wants abortion

I recently found out I'm expecting my 3rd baby with my SO. It's not planned we can't really afford another child and we don't have a very big home. My SO straight away said he wants an abortion and TBH I think that would probably be for the best I just don't think I can do it! I had one when I was very young and although it was the right decision at the time it took me a long time to get over and I still feel sad about it. He thinks im 'completely selfish' for wanting to keep it and says it's not fair as he doesn't get a choice. He says our other kids will suffer and he will have to work himself into the grave to finance it and he only ever wanted 2 children. He thinks im not thinking sensibly and letting my emotions take over. I think we can make it work and that my children will love it! Everywhere I go i see babies and im sure I'll regret it if I have an abortion but I also don't want to ruin the family life i have now. I can't talk to my family as they are very anti abortion and I don't want them to hate him. I feel like everything happens for a reason and maybe it was meant to be? Am I being selfish?