he's not "crying" because something is wrong. I would never do that. he's tired to the point of over tired. sometimes if I get him before he reached over tired then yes, he goes down happy and quiet. but sometimes I miss that window of time and he crosses over into over tired. an over tired baby will take longer to fall asleep. but I know nothing is the matter. as I've explained, he usually does a couple of wahhhhs broken up with a cough/snort, then silence. he conks out.
I thought that's how a baby fell asleep when they are over tired.
he's not screaming and definitely not for any length of time.