Should I tell my fiance I'm pregnant now or wait?

I've gotten several positive hpts and will be going to the doctors for confirmation this evening. I haven't told DF yet, honestly I'm abit scared to because we have 2 kids and no room for a 3rd plus we've discussed it and he said he def doesn't want another. I know he'll need to know but I'm debating waiting till I've gotten the blood test results to tell him. Is it wrong to wait afew days or should he know now?