What is really going on with the father of my child?

I'm 5 weeks pregnant I told my boyfriend by handing him the test so he wouldn't think I was joking. Initially he was cool he didn't say much he even smiled but the next time he saw me he said that I couldn't have this baby. He said we aren't ready for a baby but I believed it to be more than just that which he disclosed to me last night. He has two children by another woman. We had one falling out about her before because I caught him texting her telling her that he loved her. She seemed to be unreceptive to his advance and he stopped he apologized and told me he is still adjusting from their break up. 8 months later I end up pregnant and I believe he doesn't want me to have the baby because it may hurt her even tho is she engaged to another man. He believes she will use this as ammo to turn his kids against him and/or keep them away from him. I'm excited about my baby and I refuse to kill it. I told him he could leave but he says he can't do that because this is his child too. I'm so confused I don't know what to do about him. What do you ladies think?