Lost a Toenail

Hi, I'm a 36 f, non-smoker/non-drinker, and weigh 190lbs. A few days ago, I noticed the nail on my left pinky toe was loose, and it finally fell off yesterday. So far, its been painles, and I don't see signs of infection or anything. My question is why? I don’t recall stubbing my toe, there is no bruising anywhere, no signs of fungal infection, nothing. So why did my nail fall off? Should I be concerned??