Help. Discharge confusion.

Eddy
I'm 30 weeks pregnant with my second child. Last night my husband and I were intimate. Afterwards and again this morning I had a clump of thick almost snot like discharge with a brownish tint. Could this be the mucus plug? Should I worry and call my dr? Has anyone else experienced this? 
My first pregnancy I had no knowledge of loosing my mucus plug so I'm not sure what to look for. Especially with still having 10 weeks to go.