There are a number of possibilities. Your compressor may be damaged and not working properly. You can check to see if it is cycling on off properly by looking at the clutch plate face in the middle of the compressor pulley. Here is a video of compressor that is cycling on and off properly.
If your compressor is not cycling on then you should seek the help of an AC Professional immediately. Ignoring the problem will not make it go away and in fact it could make matters worse. Other possible causes are blown relays and fuses, defective sensors, or a stuck blender door. Seek the help of an AC Professional to assist you in determining the cause in your particular case.