Two month old sleeping a lot

Yesterday my two month old was particularly fussy and spitting up quite a bit. I boiled it down to him having bad reflux. I finally got him to sleep around 11 and I fell asleep around the same time only to wake up by myself at 3 and he was still sleeping. Usually he wakes every 2-3 hours to eat and it had been 4 so it was quite unusual. So I picked him up he kept his eyes closed the entire time I fed him and really only opened them while I changed his diaper. Which was a little wet but definitely not soaked like it usually is after 4 hours during the night. Does this sound like he’s dehydrated or am I overreacting? Is he going through a growth spurt or something?