Brick dust

Julia

My 6 week old woke up with a ton of brick dust for like the first time ever😭 I fed him every 4 hrs since he slept in and I fed him 3 oz of breast milk / formula. I am breast feeding but since I let him sleep through the night I like to give him bottles to ensure he’s eating enough. He didn’t pee at all throughout the night could that be the reason?