need your input

I shaved a part of my leg. I do not know how to explain this, but on the second day I get this itching, prickling, irritating feeling. This time I tried just a spot on the back to my leg. Did I do someting wrong? Is this normal? will it always be this way? It has been the last 3 times I have tried. Any help would be greatly appreciated.

Are you using a new razor? Name of the razor?

I used a mach 3. It had been used twice.