37week 4days membrane sweep

I went triage had a membrane sweep and midwife said I am a centimetre open from outside and short but internally closed but she managed to do a small wiggle with her finger .?

Im feeling funny now little bit crampy

What does a centimetre mean does it mean im not open as much im 🤷🏽‍♀️confused

Please can anyone explain.

A centimetre, short open from outside but internally closed ?

Now having suddden watery diarrhoea all week had loose stool but now its watery I’m going crazy