Mummies, how long do you usually latch your newborn? My son (12day) usually falls asleep after 20mins latching, sometimes need to top up with formula in half an hour, does this mean he didn't have enough latching time?

From discussion with my friends, different babies have different preference and duration, some need to be fed every hour, some can wait till 2 hours..some will latch few minutes then sleep while others latch for one whole hour. Breastfeed on demand means you latch your child whenever he wants it for whatever reason. Don't over think it as you not supply enough milk etc. As mentioned by previous advice, sometimes they just want comforts.