Behind in development

I’m writing this as concerned mother and ftm.

LO is born 23.1 almost 10 lb so he is chunky since birth but my concerns are that he didn’t roll over from stomach to back and reverse till he was 4.5 months old.He would come on his hip and go back on back and he done that since he was 20 days old but never went further to roll over completely.

And I saw many baby’s on this app start to crawling but when I put him on stomach he also move his feet like wants to crawl so I would hold his feet and then he would move.I first notice this in April he was almost 3 months old.

He didn’t start grab toys that are above him when he is on play mat until he was almost 4 months old.

And that big first laugh was when he was 3 months old.

I’m just worried is he going behind in development or is this normal.He is babbling,screaming (exploring his vocal strength or what ever is called so he is happy when he does that).He would hold his bottle sometimes,he starts eating solids.

I hope I explained what are my main concerns.