Telling your boss

So needing advice ladies! How and at what point did you tell your boss you was expecting?? Super nervous because this was unplanned and I’ve only been at my job for one month 😫 I know I won’t be eligible for protected FMLA leave, but I will get 6 weeks unprotected leave.. so I guess I will work my butt off to prove myself in the next month or two and then tell my boss in hopes that she will not replace me once it comes time to have my baby!?