I am 3 months pg and my boyfriend does not want me or the baby. I don't know what to do .Have an abortion?

I have been seeing someone for 6 months, he was so sweet and nice,i have 3 children from my previous marriagee, now i am divorce, but he has no kids and he wanted to be a daddy, and we both decide to try to get pg. We both loved eachother very muchand wanted to spend our future together.i even decide to move out of state with him so he can be close to his family, About 2 weeks , things has changed, it seems like his feelings came back for his ex girlfriend who is 12 yrs older then him, now he does not want me or the baby. I am upset because i thrusted him and now i am pg and don't know if i should have this baby or not. I am so confused and don't know what to do.