Holding up head

So how many of ya'lls babies are holding up their heads already? My baby is going to be 3 months soon and it seems like he just doesn't want to hold his head up. I see a lot of baby pictures on here of them holding their heads up already or trying to sit up and I just feel like I'm doing something wrong and he isn't developing on time. He does tummy time every day but all he does is rest his head on his arms or on the boppy. I know I should just be patient and he will do it when he is strong enough but I just don't want him to be behind😩