Sleeping alot

My son turned 4 months old yesterday and he’s been sleeping so much, wakes up, gets his nappy changed, drinks a bottle. Stays awake for about half hour and he’s back asleep 🤦‍♀️ normally he plays with his toys but when I put him down to play on his playmat he starts crying and yawning and rubbing his eyes, is this normal? He doesn’t have a temp or anything, could it be a growth spurt