Not speaking from personal experience but I think it means the baby will be coming within the next week or so. Since you're still a little early, I'd page your OB and let them know! GL!
In our lamaze class the teacher said it actually does not mean much. Some people can loose their mucus plug and go weeks without any happenings. She described it as an event you call your friend or your mom for, but not your OB (although I think I may still tell my OB).
Our Child Birth Instructor says that it's really not that big of a deal. Like the others it means you could deliver soon or as much as a month away from delivering.
Re: Mucous Plug?
it could mean you will deliver soon... or in a few weeks... so i guess it doesn't mean a whole lot
I'd still call your OB and let them know- I'm sure they'll give you instructions on other signs of labor to look for.
good luck!!!