Idk what to think

I am a happily married woman who has a 18 month old baby boy. He is my pride and joy. I have always wanted 2 children of my own, close in age. I wanted one more with my husbands blessing and better timing. My husband doesn't want anymore. He has two teen boys from his previous marriage. I just found out last night that I am pregnant. I want to be happy but I know when I tell my husband he will be upset. We have had some bad luck lately and he will likely contribute this to more bad luck bc of the timing. I have always been a person who believed things happen for a reason. I know everything will work out eventually but it's hard to process bc of the thought of his reaction. We were excited and tried for so long to get pregnant with my son. I had never taken birth control before him and never could get pregnant. I've been taking the pill since my son and missed a few pills this past month bc I have a hard time remembering the thing.. both my husband and I thought the odds of me getting pregnant after missing a few pills would be unlikely bc of my trouble in the past. I haven't told him and don't know how. We just bought a big house and got custody of his other two sons, so it's not like we don't have the room and help.. I'm just super nervous and want to get it off my chest. No negative comments please.