My son is 12w. when should we worry about sleep training & how should we do this? now hislongest sleep period is 6 hrs, 6pm-12am, then it's every 3hr.

Schedule arrangement: Try to rearrange his schedulr so that he takes his longest sleep between12&6. This can be done by rearranging his feeding schedule and his nap time. Rember, if you are tired and can't face the day everybody suffers including your baby. There is no better medicine than sufficient rest.

Totally Normal: Baby is appropriate for his age , longest sleep time increases at night as infant grows upto oneyear.