hi everyone m new to this so want to get to know people and ask for peoples advice. im 17 and had a baby who was 10weeks premature, he is now 9months and still doesnt sit up by himself, crawl, roll or do anything. i have tried helping him by supporting him when he sits up but just falls over. hes only just started teething aswell. is this all normal for him not to be doing anything and only starting to teethe now?