I would be concerned. You might want to pull the clutch side cover off and look at the clutch release mechanism for any problems. Release bearing starting to fail???? In the automotive industry, a failing release bearing will often screech but usually all the time the pedal is depressed.
It could be a bit of clutch noise from the plates initially slipping but I'm guessing. What type of oil do you use? Did the noise start after the last oil change?
