Baby has diarrhoea??

FTM. My girl is just shy of 3weeks. Breast feeding like a champion. I'm a little concerned about her poo tho, it's the perfect orange/yellow colour and has a bit of a cottage cheese look to it but it's very very runny and sometimes even projectile. She's amped up her eating for what I'm gathering is a growth spurt. No fever or other symptoms just really runny poo. Someone told me it's possibly just the way she poos or that maybe my milk is very rich and it's the fatty content doing it. Has anyone else had this? Should I be worried?