It doesn't matter if there's a difference... unless the number in your log book is bigger than what your odometer reads (provided it's the same car).
Yeah, that's my problem LOL. I'm a dumbass 
LOL. When's your test? If it's still some time away then you could always just take your car out and try to get the mileage up. I don't think my tester even remembered the mileage recorded in my log book. And I know for sure he didn't check the odometer because you have to press some button to see it...whatever that button is.
My test is this Friday LOL. And my car has the odometer thingy right there, ready to see

I think I might find an instructor's car last minute and use that.
mandy you can borrow my car for your test
it may or may not be roadworthy
You know, I actually wanna pass my test..
