Did your baby start saying consonants late but still have normal speech development?

my baby is 8 1/2 months old and she doesn't really say consonants yet. i know a lot of babies her age and they are all saying "b", "v", and "d" as well as strings of "ba ba ba" and my daughter only says "ahhhhhhhh". she clearly has a desire to speak but i only get that one "ah" note and then a few, gutteral, throaty sounds in addition. i talk to her and read to her all of the time. she did have her hearing checked at three months and the results of that test were fine. i am just nervous that since there are no audible consonants as of yet, this is an indication of a problem with her speech. it would put my mind at ease and help me be more patient if i knew that, all in good time, she will speak normally. thank you...