I don't know what to do... I can't get it out of my head... The baby i…

I don't know what to do... I can't get it out of my head... The baby is not a month old, this morning he was weak and tired, somehow not like himself, in other words, he woke up every day and cried... Today there was none of that... And just looked at me calmly... And as I started changing diapers, he became more active and so he was all day active... And here in the evening again (I fed him and after something happened to him, calm and incomprehensible, maybe he's sleeping or losing consciousness, blush disappeared for 5-10 minutes somewhere and normalized...) Is this normal? Or am I experiencing postpartum depression? Or am I overestimating motherhood?