Stuttering isn't always j-j-just \[like this\] tripping over a sound, it can be anything from blocks (unable to say anything), muddling 2-3 words into a jumble, or unable to get around certain words (what I do). You honestly sound lucky compared to some of us because if it really is just 2 ds or ts then those are avoidable, but yeah maybe it's a type of stutter. Speak slower, avoid those words if possible (and if you see them coming), deep breaths, hear in your head what you say before you say it, basically do everything slow motion and it can sometimes go away.