Mucus Plug

I'm 31 weeks and I believe I am losing my mucus Plug. What I had when I wiped today was about dime sized. It was clear and greenish, and jelly like. I lost it with my first pregnancy so I'm positive it's the real thing. Im wondering if I should call the doctor and get checked? Or wait it out? So far I'm not contracting and water hasnt broken. I know it could be weeks still till they come but I just want to be cautious since I'm so early still even for twins