My milk production reduced and my 3 month old baby sleeps long stretches through out night.do i need to wake him up night to built my milk production or 3 hour feeding in the morning is enough?

By 3 months most infants can sleep through the night regardless of feeding method. They feed adequately during the day. 80% of breast feeds are extracted in 5 min/side, so limiting feeds to 10 min/side & going every 2 hrs can build feeds if needed. If the urine output is every 3-4 hrs I wouldn't worry about the feeds.

Monitor his weight and growth. If he seems hungry and there is less milk supply, a supplemental formula may be offered. If he is otherwise well, feeding during the day, and growing well, he may sleep through the night. Watch for changes in growth.