Loosing mucus plug!

So I'm 30 weeks with my 3rd baby, and yesterday I was feeling crampy and hot and I noticed some of my mucus plug came out, this morning some more of my mucus plug came out and I'm still crampy.

With my first I started loosing my mucus plug around 35 weeks and don't remember being crampy I had him at 40 weeks. And with my second I never lost any of my mucus plug and I had her at 39 weeks. Should I be concerned?