Help!!!

Hello i need help with my son. I have two other kids. They never did this what he does. When we first got home 25 day ago he would sleep good. But for about a week everyday at 2 in morning tell 5 in morning he would cry n cry. I would feed him change him n wrap him up. He would go to sleep for about 10 to 20 mins. Then wake up crying. I thought he had gas so i got him gas drops. But it is not working. What should i do?? What have u mommies have done to stop ur baby from crying all night.