Firstly please make sure you wash the wound well and apply antiseptic to the wound. Make sure you also have a Tetanus Toxoid injection. Since the wound came from a nail it is very important to take these precautions. The wound need to be dressed if it is large or left to heal if it is small. You will also need an x-ray to see if you have fractured any bones. I suspect you have fractured the bone connected to your little finger. If it is fractured you will have to rest it for a few weeks before you can start using your hand normally.