Don't know what decision to take!

OK, so little background! I'm in a relationship with my amazing bf for about for over 9 month! Already have three kids that are 12, 11 and 8 from two dads (longterm relation both dads!!!) and that have special needs (one of them is in the hospital since Halloween just to give a little idea!!!) my bf and I already talked before and like he said, he helps with the three kids and don't feel the need to have "his" kid which meant we both didn't want a baby!!! So yesterday I took a test since I was late and... Yup!!! Pregnant... My decision was made, told him that I'd need him to give me a lift to get to and come back from my abortion... And he said it's OK, wasn't mad but he also asked if my idea about it had changed since we had the talk (took time to say his hasn't!) well since he asked... I don't know if I really want to!!! Haven't called like I was supposed to today because I'm still thinking about it even if I told him I was gonna... Didn't plan this pregnancy but certainly didn't think I'd hesitate to go through with it!!! Some insight? I'll obviously talk with him when he gets home, but need a "neutral" point of view!!!!