I've often said if it wasn't for bad luck I'd have none. My Mom and I have spent much of our lives (well, she most of her life) living under a black cloud that rains constantly. I've had a few better turns of events in my life, probably more in my 20 some years than my Mother in her entire life.
That said, however, there's a group of crazies out there that I may or may not be one of, that says you create your own 'luck'. You attract your own (mis)fortune. I can't say as I disagree entirely. Looking back on things, my negative thoughts have usually left me in 'unlucky' situations. Supposedly, electromagnetically speaking, a positive thought is more powerful than a negative thought, however either I'm doing this positive thinking stuff wrong, or I just don't believe the positive thoughts I am thinking.
I'm uncertain about luck, good or bad, and about destiny and fate. I'm more of a Destiny person, and I look at Destiny like a tree. Your birth is the trunk, and wherever you go (or grow, that's a plant joke) is how your tree is shaped. There's different branches and limbs and twigs and leaves and spider webs and wind and pollen to use to travel through life, and you choose where you end up by picking your path to take. Fate is so dauntingly written in stone -- I like to think it was my choice, I chose the destiny of not being a sheep, rather than I was fated to (sheeped to) not be a sheep.