My 3 mont baby is doing dark green creamy poops sincs 1 or 2 days,although she is an exclusively fed ba?

I would say it sounds like baby is not getting enough hind milk. That is the fatty milk that makes their poops look seedy and yellower. Try feeding baby twice on each side before switching. I actually only fed my son on one for two whole feedings.So the 1pm and the 4pm were on the left and the next two on the right . It worked very well and I didn't have huge ..LOL