No co2 left, is my beer ok?!

So, I'm only slightly panicked right now.....
Today was my first time kegging and I don't think I checked well enough for leaks. I put my beer in the keg, filled it with co2, purged it a few times and then went ahead with the "quick" style of force carbonating (35ish psi and rocking it on the floor for a bit). The beer didn't really turn out very carbonated (tasted awesome though, my first all grain!) so I checked for leaks by spraying with starsan around all the fittings and what not and noticed one where my co2 connects to the ball lock. I then pulled it apart, hit it with some keg lube, tightened down my hose clamp and sprayed again with starsan. No bubbles. I hooked it back up and deciding against using the quick method again, set it to 35 psi, put it in my kegerator and was going to leave it until tomorrow night and see were it was. Well.......... After a couple of hours I decided I wanted another one of my tasty brews (why not? It's my first all grain batch and it's a success, I'm proud!) and wasn't too concerned with the lack of carbonation. I went to purge the tank to reset the psi to pourable and noticed only the tiniest hiss. I pulled out the co2 tank and it said it was empty!!!!
Is the lack of co2 in my keg going to hurt my beer before I can pick up a new tank tomorrow?
Also, what is the best way to check for leaks? I had figured starsan bubbles enough to have the same effect as soapy water, but maybe it wasn't effective enough.
Sorry to ramble, just wanted to be thorough. Thanks for any help in advance!

Whoops, just saw the thread below mine..........
Anyway, I'm still curious to know if purging my tank let out too much co2 for the beer to be protected.
Get used to seeing my name around by the way, I have A LOT of questions

What diameter is your line? How long? What type of beer? All of this matters.

Check your o-rings, connections, regulator, etc.

Beer will be fine. Take the gas disconnect off the keg though. When you get the new tank, just keep carbonating the beer. Worst case (fully carbed beer going flat, and re-carbing) the beer just loses a little character - nothing terrible. Make sure the O-ring on the gas post is in good condition. That has been my biggest issue - gas post not sealing perfectly and leaking. I would turn the gas on at 30psi but don't attach it to the keg. If no visible/audible leaks, and your gas is at the same level the next day, hook it up to the keg. If it leaks then, it's the gas post. Good luck.