39+2 and lost my ENTIRE mucus plug

Y'all. Sitting at work and I thought my water broke. Went to the bathroom and was just a huge chunk of mucus. I mean huge. Have been feeling like my period was about to start all morning and when it came out I had an immediate relief of pressure. Now I'm sort of shaky but it could be the coffee I just consumed. So could it still be a few days before baby or what?! I know it's just a guess and I'll be seeing my doctor tomorrow. Just curious for others previous experiences. Thx.