Ahhh! Why does my lip keep twitching?

I started taking Ambien about three weeks ago and it was great. I had no side effects and I slept like a baby. Then I stopped using them after two weeks like the doctor told me to do and my sleeping habits are fine now...but I noticed that the first day I didn't take it my upper lip starting twitching involuntarily once or twice a day. It's been about a week now and it's gotten worse. It now happens every couple minutes. When it happens my lip starts to feel numb. I guess it's not really that painful, but I kinda look like Elvis sometimes. LOL. Could this be my body's way of adjusting to being off of Ambien or should I go see a doctor about it?