I'm going to have an abortion behind my boyfriend's back
Why would you not tell your boyfriend about an abortion?
He'd hate me if he found out he got me pregnant.
Even if he is mad about it, I still think he has a right to know about the abortion. You should consider telling him about it.
I got a response from him saying this is not his baby. I'm going to have it anyway.
That must have been very hurtful, and he is probably fine with you having an abortion. You still should tell him so there is closure to the situation.