HELP SHOULD I BE CONCERNED

My baby is not yet babbaling or saying mama dada Gaga nothing like that he is ALMOST 7 months old he will be in about 2 weeks the most he does is when I talk to him he will sometimes respond with MMMMM or scream but it takes a really long time of me talking to him for him to do that and that’s all he does he doesn’t any “chattering” or anything when he cries and when he is upset he will literally say “MOMMMMM” obviously not on purpose but thats it, should I be worried is this normal?