I'm don't wanna tell

I'm pregnant with my second child my first baby passed away my partner didn't wanna try again right away but whoops I'm pregnant now. I do not want to tell him I'm pregnant idk why i feel like I've done something wrong I know it takes 2 to make a baby but he's gonna be so ANGRY 😔 it's my rainbow baby so I'm excited I don't want him to take that away from me even his mom said don't tell him yet. (he is not abusive) at all my dad would kill em... But I just know he will be mad and don't wanna deal with that especially not now it's still really early. Am I wrong?
I'm positive he will be PISSED I'd like to think he would be as happy as me with the rainbow but I think he was content he has a son from a previous relationship and made it kinda clear he didn't want more right now he wasn't even happy about the one we lost he came around towards the end before I lost the baby