3kids and an unsupportive husband

I have three kids one has severe autism at 7 years old and still pees and poops in his pants. My youngest is 16 months old. Long story short condom broke and now I might be pregnant. He said if I get pregnant he doesn't want this kid and he would probably die...should I even tell him or should I just get it "taken care of" I've never wanted an abortion and we can take care of another child financially and everything (he's military so I we have great help with my oldest) but I just feel like I'm alone in this....thoughts?