The last couple of nights our little guy is not sleeping well. Our normal routine is nurse him around 9 and put him down asleep when he's done nursing. He was sleeping from about 9:30- 6:00 but now will wake up about an hr after putting him down and sometimes we cant get him back down after that. He will be 4 months in 5 days. Is it time to sleep train? He's been sleeping in a pack and play by our bed , but was going to switch him to his crib this week until this bad sleeping started.