This is one of those 'small things' too many Christians can be hung up on. It was an accident. Forget it, get over it and move on. Don't worry so much. Remember, all actions stem from the heart. And God looks at your heart and intents behind your actions. Its when your intent to disobey God comes into play that you should start worrying the most. But we all slip up, make mistakes, maybe cuss when we stub our toe, haha. While it's best to try to catch yourself, sometimes things sneak past us. Just talk it over with God and move on. The more you dwell on mistakes (or perceived mistakes, as in your case) the more you allow satan to infect your relationship with God.