Oh you poor thing - that is such a sinking, awful feeling. Yes, sadly, I've had the same thing happen and my luggage has been lost with international travel. It is SUCH a pain!
In case it hasn't been mentioned already there are a couple of things I suggest: Check the airline policy/your travel insurance and see if there is some sort of clause which entitles you to a compensation payment if your luggage has not been returned to you within a set period of time (something like 48 hours). Also, be aware that the airline will generally pay for your bag to be couriered to you when it arrives - there is no need for you to go to the hassle of driving all the way to the airport to pick up your bag.
I always had to giggle at the fact that my bag was more well travelled than I was!
Best of luck, I hope it is safely with you very, very soon!
