I cant remember if this was the thread with people speaking of the clutch master cylinder but.. i need some advise on this asap as i need to take it in if its it.

So before my clutch burned out (stock clutch came with the car installed) it was quite heavy. The first month or two i got my new one put in (cushion button exedy clutch) it was quite loose and i loved the feeling. So recently i've noticed it gets tight and loose randomly.. usually when i give it to the car at high revs like jumping on the freeway it loosens up abit.. But other then that its really tight like it used to be but with this sticky feeling behind the clutch pedal i've looked behind my clutch pedal and theres nothing there (no idea how to check if its leaking i just assumed if it was leaking it would be behind the clutch pedal) anyway any help would be great