I'm 36 weeks pregnant & i've been losing my mucus plug for a week or so & having fairly regular & painful contractions. is labor imminent?

Depends: Definition of imminent? In next few hours-Prob NOT In next few days-Possible In next few weeks: Probable. Once as a 3rd year medical student on OB rotation, a woman in labor asked if she would deliver in the next few hours, I replied yes. When the attending OB hear of this, he suggested I sit with her until she delivered. After 8 hours of labor, delivery occurred. I learned about predictions!!