Fate vs. Destiny

I think that choice turns into fate. For example, if you choose to go to the grocery store after the show you are watching on tv is over, you are choosing your destiny. When you do leave the house, you could get in your car and in the intersection waiting to turn into the grocery store you could be hit. On the other hand, say you try and go to the grocery store on a commercial. On your way back to the car you could be mugged. I understand that these are kind of extreme examples, but I am simply trying to make my point. You choose your fate.
As for Oedipus Rex though, I do not think that fate was something that was a factor in his life. He never chose to be given up by his parents. He never chose to fall in love with a woman who was, unknowingly, his mother. He never even chose to be born, of course. Him falling in love with his mother was his destiny, just as each one of us is destined to fall in love eith a person at some point in our life. I think that fate is a factor in destiny, though. If Oedipus had waited another ten minutes before traveling, he would have missed the carriage that had his father in it, and he would have never killed him. Therefore, despite the fact that he did fall in love with his mother, he never would have killed his father.
But, just like anything in life, it is what you make it.