4 month regression

is anyone concerned about the four months regression right now I transferred my baby to the crib for naps and overnight sleep with the Merlin suit from The Rock and play but I do have to rock him to sleep so usually takes about 10 minutes of rocking and then I put him in the crib but I heard for 4 months that's when they're permanent sleep starts and so if you rock to sleep every time they wake they expect to be rocked so now I'm nervous I've heard some people sleep train during this time