Brown discharge... 37w4d

I've been having gross amounts of straight up brown discharge and clumps of something like. Mucusy in it.

I'm honestly getting worried as to what it is.

I've been having contractions since 11pm last night, had a doctors appointment at 1030 this morning & got a cervix check. Which I had one 2 days prior as well. No more dilation, was at a 1/50% effaced. Got home, did my normal activities of cleaning and felt the rush of fluid. I've now had the 2 pads photo'd and another pad NOT pictured with this brown discharge.

I know they say it's normal after a check, but when does the amount become concerning?