membrane sweep?

I am due November 19th with a baby girl 💗I've been having lots of Braxton hicks, random cramping in my back, fatigue, and I had slight brown discharge a few days ago and shortly after saw some tiny pieces of mucus plug. I have 1 more appointment scheduled for 40 weeks & 2 days and if I make it till then my Dr. wants to check for dilation and do a membrane sweep. What does a membrane sweep feel like?! Do I sound like I may already be dilated slightly? First time mom ☺️