Just to add to the wisdom already imparted - it is a perfectly natural reaction to check out your son's development against his peer group, but it is futile, and will only give you stress.
Children are individuals, and all develop individually. Deveopment is a natural process, not a race, and there is no prize at the end.
If you are worried about his potty training and rinking, stick your head round the local primary school year One class door - how many cyhildren are bottle fed and in nappies? None! They all get there eventually.
Boys' speech develops more slowly than girls, that's just a simple fact, so he will come to it in a rush, and you'll be wondering why you didn't enjoy the peace when you had it!
All joking apart, children are a miracle of nature, and their differing development rates are down to a bewlidering variety of circumstances - but parents are way down the list. It is as pointless fretting about your son's development as it is for others to boast about theirs being quicker - these are babies, not hothouse tomatoes!
Take it seasy, stop streeing yourself, and enjoy watching your little one discover the world at his own pace. If you are still worrying, have a chat with your health visitor, to set your mind at rest.