Smile, it is what it is. Don't assume the worst, even when stuttering. Smile and no need to worry about it. People would worry about anything when approaching girls at the gym. Props for doing it. Imagine it going better in your head and understand that those kind of growing pains where whether you stutter or just wish you did something different or didn't say what you said happens to the whole world over and over. It is what it is, smile more and that tends to put people and ourselves more at ease.