Because this is my name! I know you've already decided to go with the Amy spelling, I just wanted to comment I like the AmyJoy nn. My name is AmyJo, and I was called AmyJo until I got to school and dropped the mn. Honestly I'm surprised to see anyone on here considering my name...
AmyJo is nice too but I prefer AmyJoy's lightness and how it mimics the sound of Joyce. So do you like being named Amy? Do you find lots of people with your name or not very many your age? I'm really hoping to use Amy some day, I so love it's simple beauty! :)
I understand... my middle name is actually after a man named Joe. I went to school with quite a few Amy's, but I was born in 1985, and it was a very popular name back then. It's not even on the top 100 anymore here in the states. Very nice choice, indeed. =)