I Don't Know What to Do

When I first told my boyfriend about my pregnancy, he was really excited! But then one of his sisters (who I DO NOT get along with) started telling him that the baby couldn't possibly be his. The reason why is because we had been broken up for a month, and she misrepresented the fact that my close (male) friend had been coming to the house to see me, and used pictures off of our social media to suggest we were together during the month my bf and I were broken up. I've known the boy for 12 years, and we've NEVER felt that way about one another , so obviously we weren't together (he's my ex-stepbrother ) But it was enough to make him doubt both me and my pregnancy. Even though we've all sat down (his sister, my friend, him and I ) and explained that it was impossible that my baby was anyone's but his, and he said he understood my friend and I weren't in a romantic, or physical relationship, he was still questioning me for days trying to see if I would change my story, and went onto my social media behind my back to block my friend. At one point, he even tried to force me into an abortion, because he said that he could "just get me pregnant again" but his mom and dad, who both know that I was stuck on their son the ENTIRE month he had left me for another girl, talked him out of that mindset. While he claims that it doesn't bother him what his sister said (and is STILL telling him in texts and phone conversation )he's constantly throwing in my face that he wants a paternity test, and he keeps telling his family that he's not going to help me with baby stuff or appointments until he gets one. Of course I agreed to him having the test, because I didn't do so much as look at anyone else while we were on that break, but he's dragging his feet with scheduling the appointment, and refuses to have me do it. The final straw for me though, was when we were at dinner with his parents he even said that if the baby was his he still wouldn't sign the birth certificate, and that instead my friend could. I was SO hurt and offended that I broke down at the table and had to sit in the damn bathroom for a long time until I could go back, and I still couldn't face anyone which made the rest of the evening awkward and quiet. But instead of realizing he was being insensitive he got pissed at ME and told me I ruined the occasion by crying over that "little comment", and that he should have taken his ex to the dinner instead, because she "wasn't so childish ".I've tried to explain how hurtful it is for him to throw me on the Hot seat because of a false story, but he is just getting more and more distant, moody and aggressive. It's affecting how I feel about myself, especially because caught myself wishing I wasn't pregnant at all, but when I try to have serious conversation with him he brushes me off and says I'm being sensitive and needy. I didn't think so at first but now I'M convinced that I brought this on myself by turning to my friend for advice and comfort, but I don't have anyone else I trust enough to confide in or to talk to for help. At this point I feel like he doesn't even want to be with me.