What does a mucus plug mean, what to do next, what does it look like, is it a sign of labor, and more! Mucus plug questions answered! Losing the mucus plug can be alarming. If you're a first time parent and wondering about the size, color, shape, timing, if it's discharge or bloody show, I've got answers. Click through for all the information to put you at ease while in the last trimester of pregnancy on the cusp of labor.