One of the biggest challenges new parents will encounter is how best to settle and soothe their new baby to sleep (along with working through their own sleep deprivation!) Believe it or not, most babies need to learn how to 'fall asleep' and how to fall 'back to sleep' when they experience wakeful times, or 'light sleep' within a sleep cycle (so much for the saying 'sleep like a baby'!).
Babies (like most small creatures), initially need to feed frequently for nourishment, and their instinctual needs are the main reason they will wake frequently overnight in the first couple of months. This is the case, whether they are breast or bottle-fed. Babies also need to adjust to digesting their food, and can become unsettled at times, (for example when the milk comes if breastfeeding).
How 'settled' a baby is will be very individual. There are no rules, nor pre-warnings, for how your newborn baby will behave in relation to their sleep. Some babies will be unsettled from the very beginning, or after a few weeks. For example some babies can have a 'transitional or settling in' phase for a week or two and then become more wakeful, fussy and unsettled later on. This can often leave parents wondering why their 'good little boy or girl' is behaving so differently. These wakeful and unsettled phases are very normal and are experienced by most babies. Be aware too that babies will have 'good' and 'bad' days (as we all do); therefore it is not unusual for them to be settled for one day, then unsettled the next.