Announcing you have a stutter in a presentation

Announcing you have a stutter in a presentation I'm 23 and am doing a presentation to my research group next week about some physics i have been doing. Been thinking about announcing I have a stutter at the start of the talk but not sure whether I should or how to phrase it. I used to be pretty good in presentations (not particularly worse than normal) but on recent occasions at other universities (with time pressure) I have had a nightmare. Any thoughts? The group is fairly informal.