I'm not sure but if you lost your plug prior to 37 weeks you should contact your dr immediately. Hope all is well!
should look like blooding mucus.
It can be clear, cloudy or even have a yellowish tinge to it. Green might be the sign of infection. Black, brown, red means blood and should be reported to your doctor immediately at 31 weeks. In fact you may want to go to urgent care if you are having any bleeding at 31 weeks.