Isn't all the best images in history, luck? Capa, Cartier Bresson, you name it. Their best images are just luck. Not that i say it, THEY say it. Your skill is to be aware of the opportunity and happen to react and click. And you did an amazing job at it!.
As for the flickr thing. That is personal. some people love to share their images, others like Vivian Maier never showed any of her work to anyone. Its your call, but if it weren't because you posted this image here, i wouldn't be writing this, right?.
whatever you decide, if i were you, id print it and frame it and hang it on the wall.