Baby pooping

Okay so I had my daughter six days ago. I am exclusively breastfeeding and she is doing great with it. My milk came in Monday morning. I feed her about every 1.5 hours. Sometimes it will go to about 3 hours because she is sleeping but never much past that. I feed her on both sides and she definitely seems to be getting full. She passes plenty of gas but hasn't pooped since Sunday around noon. That was the last of her meconium poop. Can someone ease my mind about it being so long? She has plenty of wet diapers. She has a dr appointment this afternoon.