Yummy mummy I am glad that you popped in to the hospital and had a swab taken. Anything a bit unusual should be checked out.
Green discharge can mean infection but it also can be due to the hormonal changesin pregnancy giving a bit of unusal colour to your vaginal fluid. I would err more toward movement at the station - your vaginal fluid will be whitish yellowish and that mixed with a little brown makes green! This is something that is not at all unusual this late in pregnany when your body is preparing for labour. Your 'mucous plug' doesn't necessarily come away all at once and can be slowly bit by bit. Sometimes the 'plug' is greyish, bright red streaks, dark red streaks, brown and yes even a bit yellowy green.
Lots of good labour vibes to you as within the next couple of weeks your baby will be here!