I think I had my bloody show last night...but I guess I expected the rest of the mucous I'm passing to also be streaked with blood. (I'm still loosing a lot of MP every time I wipe). It hasn't been though! I can't really find any straight answers online either. I guess it doesn't really matter, but I'm curious if that was really it or not!
Re: Is bloody show a one time thing?
It can be either. Bloody show is caused by blood vessels rupturing as your cervix dilates and/or thins out. Dilation and effancement don't always cause the vessels to rupture early on, so you can easily walk around 80% effaced and 2cm dilated without bloody show. After that, generally you are dilating quickly and the blood vessels will break, so you will have bloody show in active labor. Everyone is different though, so you can have some bloody show and not go into labor for 4wks, you might have it off an on for 2wks, or you might not have any until labor starts.
--minor edit to fix a typo--