Is it possible that when you bleed the air out of the clutch. That if you miss some , later it makes its way to the resvoir and causes the fluid level to drop? I'm talking a couple or more weeks?

 

If you left air in when bleeding you'd notice - air compresses, hydraulic fluid does not. The mushy clutch feel would be a giveaway.

But to answer your question, yes it's possible. The bubbles could slowly make their way through the lines to the reservoir.

 

If your clutch works at all, then there isnt enough air in the line to affect your resevior when it comes out. If it went down then It is probably leaking somewhere.

 

Just replaced the cluthch hose a few weeks ago and yesterday it started acting like the clutch was sliiping same thing it did when I sucked in some air with the bad hose. Fluid level was still within the limits like 1/2 way between min and max. So I filled it to the max and its been fine. Go figure?