seriously, don't ask here, ask your HR /Payroll

since every company handles things differently, they may have already update your info based on our EAD, in that case, you ARE using EAD.

So talk to HR/Payroll, make sure they do what you want, that is start EAD from march next year.

One extra point, your status may also affect your tax status, tax withheld. So no one here can help you, only your company's HR can.