my bloody show personally was more like a period bleed than mucus and i was 5cm and induced that same day... of course i was having contractions and went to hospital twice day before that... so depends on your contractions really
I was induced and while I was in labor we saw the bloody show and that was at least a few hours into labor.
With my son, I had one on a Friday and was induced the following Thursday. So, I guess I can't say for sure when I would have actually gone into labor. My doctor wanted me to induce because I was in the 41st week. I have heard it can be 1-2 weeks, though between having one and giving birth. Some people say it's only a matter of days, though. I guess you never can tell, but at least you know it'll be relatively soon! :-)
i have one child and never had a bloody show with her, but iv heard it can even take up to 10 days before labour begins