How did I get my stutter

How did I get my stutter I've had a mild stutter for as long as I remember. No one in my family has one, as far a I can remember. Some people think I got it when my mom dies when I was 7 but I've had it much longer than that. Is there a way to get it when you're a baby? Also I'm not entirely sure what constitutes as a "mild" stutter. I stutter my words, mostly and or the or a word like that, not a whole lot, as in I can make it threw a conversation with only stuttering a few times.