is this my mucus plug? tmi/graphic

im 37+4, 4cm and 70% thinned as of yesterday. ive been losing big chunks of mucus for a few weeks now but this mucus is brown. its 45 min to the hospital and i was just there yesterday and i dont wanna drive unless i have too. what is this???

*note that im having contractions this morning too and a lot of cramping