Almost 10 week old won’t sleep at night!

Micah

Between 4 through 9 weeks my son would go to sleep at 11pm and slept throughout the night and wouldn’t wake up until 4/4:30a.m.

Since a couple days ago, he takes a nap at 9pm wakes up at 11pm then goes back to sleep after he eats and wakes up again at 1:45/2:00a.m and then goes to sleep again at 3:45a.m. And doesn’t wake up again till 5:30/6:00a.m. I don’t know what’s going on, How can I get him to sleep throughout the night again?!