40 weeks copious discharge?

Due date is tomorrow. I'm already 2 cm dilated and 90% effaced and baby is engaged as of last week. I lost my plug over the weekend and now today, 4 days later, I am having periods of copious discharge. So much that I need to change my underwear. It is mucus-like (snotty)consistancy and slightly beige. Is this still plug? Should I call my Dr. or wait until my appointment tomorrow? I am not having any contractions as far as I know. Thank you.