You’re not alone. It’s the same thing for me too. As others have said, it’s pretty unpredictable. The best thing we can do is to accept what happened, understand our emotions, and recognize what is the next steps forward. I work at a tech company too. I stutter too. I sometimes get red and cannot think of anything else but how I fricked up my words in a casual context. But, I let it go and focus on doing my job. However, I told my boss about my stutter and asked for any other improvements… he said that he would have never known this I have a stutter.