Need help formatting my one-act play.?

[Bobbj]

I have written a one-act, one-character play. I guess technically you could refer to it as a long monologue. But for the record, it is not just a monologue in empty space with no context. It has a beginning, middle and end just as a full-length play would. My question is, I know that the standard playwriting format has been designed so that in your final draft, one page of dialogue approximates one minute of stage time, well if there's only one character and thus quite a bit of speaking, should I double space it? I've even timed it double-spaced and it yields about a minute's time. I just don't wanna totally seem like an amateur for taking this "liberty". Thanks so much in advance everybody.