Opinions on prenatal paternity test??

There's like a 25% chance the baby girl im having in 11 weeks isn't my current boyfriends. We are both young and this was an unexpected pregnancy and he says he loves me but doesn't want the responsibility that comes with a child if she isn't his own. I understand I guess but to me that means if it's not his we are breaking up which sucks. I don't want to wait until she's here because I don't want his family buying me a bunch of stuff if she isn't his. They are all so excited for her and have no idea that it could possibly not be his. Since my periods are so irregular and my memory is so bad I just can't find comfort in anything and the closer my due date gets the more stressed out I get. I don't want the invasive test but nowadays they can do the test from my blood work. I guess I'm just looking for opinions and advice about what I should do..