Help please!!!! Call L&D?

I am 18weeks 4days and today when I went to the bathroom I noticed a huge blob of mucus in my panties and my panties a bit wet. I got a little nervous because I thought it looked like a huge chunk of my mucus plug(there’s no pink or red color to the mucus). Then when I started driving home I noticed my lower back hurting on and off and maybe 5-6 cramps in my belly. I’m in a warm bath right now relaxing, trying not to stress, and drinking water. Should I call Labor and Delivery to be safe?

I have no history of pre-term labor like this, so I’m confused at what could be going on.