My DS who is EBF is now 4 months old. He's always been a very efficient eater with feeds normally lasting under 10 mins. He will happily got 3-4 hours between feeds as well. Starting on Tuesday he was very fussy all day and since then has been. His feeds are now 25+ mins and he sometimes doesn't seem satisfied afterwards. Last night he ate for 1 hour and took 60ml if expressed milk and then ate another 20 mins. Is this just a growth spurt and how long should it last? I've been trying to feed more (every 2-2.5 hours) often but am I going to start bad habits?