Green/foamy poop

Kittery16

I feed DD on only one side each feeding.  She usually nurses for about 15 minutes 7 times a day (every 2-3 hours, STTN).  I don't see how I could have an oversupply... I never have any pain issues, even going the 8 hour stretch at night.

Lately her poop has been green and foamy, sometimes mucousy. She has wet diapers for every feeding, and usually 2-3 poos a day.  She sometimes screams with gas and bowel movements.

We have her 2 month appointment tomorrow, so we will ask the pedi about it, but does anyone have any insight/advice?