Def not! My best friends daughter is the same age as mine and my little one did everything before her and she was really worried. By the time they started school they were exactly the same - neither was more advanced than the other! He sounds perfectly normal!
No you should not be worried. Your DS is perfectly normal! Babies learn things at different times, they are all different. Talk to your son, read to him and cuddle him and he will continue to be perfectly fine!
My little boy is 13 months and only says dada mama and tarh he babbles like baby words. A girl i know has a 11 month old and she says all sorts. She has a 3 year old as welk but i dont have any other babies. Is this something i should be worried about or not?