My nail has turned black after i got it caught in a car door. should i be worried?

Maybe: The black is blood which has pooled under the nail. It may take several months for it to grow out. If an odor develops, it may indicate a bacterial infection and you may need the nail avulsed along with oral antibiotics. If you press on the nail and fluid is still coming out, i would see about having it removed. It may or may not grow normally ongoing.