1st leap and no sleep

Hi 

my newborn is 4 and 1/2 weeks pregnant and is going through his first leap whichever means no sleep for me. He only sleeps when he is on me when I put him down he literally screama the house down. He was sleeping really good before. Does anyone know if sleeping routine will come back and if so will he be able to soothe hisself like before?

also how long do these 1st leaps really last for? 

thanks