Just tell him you made your choice to keep your baby and start preparing to be a single mom. Child support will take awhile to kick in, if he signs the birth certificate, then a court ordered paternity test takes longer so, I hope you're housing and financially stable. Save as much as you can now for childcare so you can return to your job as soon as possible.

Hopefully he'll step up and you can properly co parent. Even though you have made this choice without any communication or discussion, have lied for weeks, and have given him the silent treatment. (All great signs of a truely responsible, mature, intelligent adult that should be trusted to raise a functional human) The sooner you stop with the games, put on your big girl panties, and tell him the more you can plan.