I don't know if this is a type of stutter or not.

I don't know if this is a type of stutter or not. So I often stumble over words, jumble them up, mumble them and something slur my words this happens quite a lot. The more I think about what I'm going to say the more I stutter but like actually stuttering as in double letters at the beginning of words letters like b,d,p etc. So if I'm thinking about what I'm saying I stutter more unless I avoid specific letters. Edit:I don't stutter if I switch to a different accent that isn't my own and involves actual thought. Or sometimes I'll know what I want to say but end up saying the wrong thing or slur my words etc.