My first question is, if you are new, why do you think the breeder miss-sexed it? Like the person above said, we can't tell if you are popping correctly so we can't say for sure one way or the other. If you don't pop correctly a male can look like a female, plus that's an older snake-so it's stronger. Majority, if not all, breeders know how to correctly sex a snake. It's not impossible that snakes get miss-sexed, but it doesn't happen all that often.
I would take the BP to a breeder and have them sex the snake if you really want to. Popping/probing can be dangerous for a newbie to be doing. You can break their spine or rupture their sex organs. Just something to keep in mind.