Description of mucus plus? Don't worry no pic

I am 39 weeks and my doc did a membrane sweep yesterday. Was 1cm dilated and my cervix felt a lot softer than the week prior according to him. My husband and I had sex after the sweep to hopefully get things going. 
This morning I had a some discharge and a very small amount of small brown tinged cm. Throughout the morning I had stringy cm that looked as if I was ovulating, but haven't noticed any since.  Is this my plug or would my plug consist of more? I really hope she comes tomorrow- my doc would be ok call!