Anyone have a 1yo who hasn't said ma-ma?

Beebee09

DS is such a blabber mouth, he is constantly babbling all day but all he really says is da-da and duuuuu.  I've heard one or two "no"s and "na" but no ma?

I thought mama and dada were milestones for 1 yo so I was a little confused/nervous.  I try to practice with him but don't really have any ideas for increasing vocab.

Anyone in a similar situation?