Starting Question

Got in the car this morning all electrical systems appeared to be working (lights, horn, etc). Turned the key - Click. Turned the key again - Click. Turned the key again - Click. Turned the key again - Starts like nothing was wrong. Drove the car about 30 miles, came home, car starts right up. If I keep the key in the start position, foot on the break and depress the clutch, it has the same effect as turning the key. Am in correct in assuming that this eliminates the ignition switch from the list of possible causes? Also the battery terminals are clean. This has been going on for about 1 week or so. Any thoughts on how to track down the problem. I don't want to replace the starter and find out later it was something else. I am afraid that one day it won't start at all. Thanks in advance.

check the ignition and check the clutch starter switch