A/C Stopped Cooling

First thing is to check the A/C sight glass under the hood. There are instructions on this site, but basically you should not see any bubbles in the line (until you turn the A/C off, at which point you will see some foaming). If there are bubbles, then you have a leak somewhere. If you see no bubbles, and no foaming, the system is about empty.

 

not much you can do your self, but as nh70 said check for bubbles but if there is almost nothing or if it is 100% full ether way there will be no bubbles. You say you can hear the compressor kick on if you are vary sure it is the compressor that is kicking on it is at that point if you are looking at the sight glass you will start to see the refrigerant move. You can look for some leaks it dose not always leave a oil sign but some times dust and dirt will build up at the place of the leak. I posted some photos in my album you can look at to see a common leak point and what to look for. Use a good strong light and fallow all the lines from the compressor to the condensed then from the bottom passenger side of the condenser fitting up to the high side service fitting , sight glass, pressure switch then back to the firewall and you can see the other low side suction line larger coming out next to it going back down to the compressor. You can have other problems to that control your under dash air control doors or other things.
Have a hybrid shop or dealer look for trouble codes , then they depending on what they find they may look for leaks , recover the old refrigerant out, ( ask them how much refrigerant came out if they do) replace a leaking oring or replace the leaking part if that was the problem and add a trace dye to help find future leaks.

PS. if it dose turn out to be a leak and all 100% of you refrigerant leaked out ask them to replace your dryer shock in the condenser. But if all your refrigerant leaked out you would not hear your compressor come on. would like to hear your final out come.