For as long as I can remember my lg has been having these through the night. She is now 7 months. Some nights she screams once or twice and some it's pretty much every half hour to an hour. She never wakes up and is usually consoled with a gentle hushing but sometimes she screams so heartbreakingly and she only calms when picked up and cuddled. I understand the theory behind why they have these, but how long will it go on for?