Turntable speed

The last days ive been hearing my records and they sounded a little different than before when i first used it, i got it like 1 month ago and a few days back I noticed a sound difference, the records sounded a little too fast and I wanted to know how fast the turntable was going, I used this app and it says 33.80 or something, and i dont know if it is good or bad like is a average speed or should I do something to fix that