Every time I use the sink or shower either in the kitchen or upstairs in my bedroom, I hear this sticking or knocking sound from I corner of the house where the pipes run. There is no leaks and I have lived here for 8 months now and I noticed it shortly after moving in. I did not hear it on the inspection. Do I have a slow leak?

More likely that you have pipes that are rubbing against the wooden studs or joist. You probably hear this when the hot water is being used. The hot water heats the pipe and it expands. It will rusually make a little popping sound. It will do this again after you turn the hot water off and it begins to cool. If you can get to the pipe you could put something between the pipe and wood to relieve the sound but usually the pipes are in the wall and are not accessible.

Harold nailed it with the "rubbing pipes". Let me explain it a little farther.
Knocking, popping, creaking and crackling pipes are a common complaint, especially in colder weather. I can tell you what's happening and take the mystery out of it but you're not going to like the repair. When a draw is made on a hot water line the line expands against a pipe strap next to a stud and when you drain hot water from your tub or shower it goes into a chase that is a little cooler then room temperature. The heat expands the pipe causing it to rub against the stud to which it is pipe strapped. This is the sound you hear. As it cools it contracts and the noise is heard again. To repair it you must tear open the walls and locate the pipe strap that's causing the problem and shim it tight. Most people when they learn what causes it just elect to live with it. Regards, Tom