Am A Mom Of 2 Month Old Baby. He Is

Am a mom of 2 month old baby. He is not all sleeping at night and even in day. When we lay him down he starts crying at night. In day time he simply plays and dies not sleep . he used to sleep by 4am and wakes by 11am and that's his sleeping hours. He repeats the same every night for more than a month. Am worried when the situation will change?