Baby cries badly before sleeping: is it normal?

Is it normal for 4 months old baby to wail about 1-5mins before he falls asleep? My baby cries badly whenever I put him on bed to nap or even when I carry him to pat. He will eventually fall asleep but he will cry before that. Can see he is tired because he started yawning, rubbing eyes. Is it because he is overtired? I thought it was because he is overtired hence the cries so I tried to put him to nap once I see him yawn but he still cries the same. My heart breaks when I see him cry like this every time before nap or bedtime sleep. Any insights? :(