Mucus plug?

Amber • SAHM to a beautiful, smart, energetic 2 year old boy and his newborn brother!!
I am 32+2 with my second and lost a big chunk of my mucus plug tonight when I went to the bathroom. As of 3 weeks ago, I was already dilated to 1-1.5cm, but not thinning. Should I call my dr tomorrow? I didn't lose my plug with my first until the day before I had him.