Tidbits in Exodus

One of my goals for this summer was to read through the Bible. I do not have a set amount that I read each day (although I probably should), but rather I read as much as I can each day. Lately, I have been crusing through Exodus which has just been awesome, and while I was going through the Egyptian bondage scene I came across a couple of things that struck me.
First, what popped out at me was the two powerful signs which God shows to Moses when he meets God at Horeb (Ex. 4) in the burning bush. Moses questions God by assuming that the children of Israel will not believe that Yahweh had sent him. So as you know God powerfully displays to Moses that He is God by turning his staff into a snake and by covering his hand with leprosy. For whatever reason, I ALWAYS thought that Moses and Aaron performed to Pharoah (via the Power of God) both of these powerful signs. However, according to the Ex. 7 account they only performed the staff and snake sign. I could not find in my reading where Moses inserts his hand into "bosom" (KJV) and it becomes leperous before Pharoah. Any insights on why I always thought that Moses performed both signs before Pharoah (other than the fact that I have watched Hesston too many times!)????