Has anyone's stutter changed since childhood? (Evolved?)

Has anyone's stutter changed since childhood? (Evolved?) When I was younger (been stuttering for as long as I can remember) I would stutter like so: "M-m-m-mom c-can we go to th-the m-movies?" Around fifth and sixth grade it went away completely (yay), and I thought I was done forever, but with 7th grade (and puberty?) it came back--evolved. Since then I stutter differently. Instead of "M-m-Mom" I just can't start the word. It's hard for words to come out, and my head would nod violently in a struggle to say a word. It's more under control now (once my head went batshit crazy) but I'm curious, is this form of stuttering common? Also, can a stutter really change its behavior like that? Any advice/suggestions welcome!