Mucus Plug maybe TMI !!!

i'm due november 6th, i went to my doctors office today since i'm 36 weeks 4 days he did a culture swap and after he was done he said it's spotting which is completely normal. but i never see or have signs of spotting. i did realize whenever i use the bathroom the tissue would have brown spots on it or in my panty liner but i didn't think it was from spotting if you know what i mean. any body has the problem ? does it mean i'm slowing losing my mucus plug? & also when did your doctors start doing cervixcal checks? my doctor said he does them at 39 weeks. but how am i suppose to know if i'm dilated, or if my cervix is opened, closed, etc..?