every baby is different....both my children cried very little and when they screamed as you describe, almost always that signified discomfort; or trying to get our immediate attention....you could try different things untill you figure out what your baby is wanting or needing......our daughter would scream like that until i drove her around the block in the car and she would calm down immediately, my son would fall asleep in the middle of an aisle at the grocery store when he needed to take a nap...he never screamed unless his hands were dirty or sticky and he would go beserk and is still like that today..........good luck, don't worry be happy!!!!!!!!