It doesn’t sound like cause for alarm. When you say “fell down”, do you mean stumbled or tripped? Reading your comments, I get the impression that you simply were distracted and not aware of your footing. As it is, it sounds as though you’re in good condition, since you managed to hop up quickly more concerned about embarrassment than physical damage. It sounds like a one time thing, and clearly you had the necessary reflexes and agility to handle it.