I listened to a lecture by an alcoholism specialist from Dawn Farm in Michigan recently. The lecture is available as a podcast on iTunes if you are interested. He described the characteristics of an alcoholic and explained that alcoholics can go weeks or months without drinking, so abstaining for a period of time may not answer your question. He said that the best test for alcoholism is to buy a good supply of your favorite drink and then have one and only one drink at the same time each evening for one month. Apparently, no alcoholic can pass that test.
I have questioned from time to time whether I'm an alcoholic, as my drinking patterns are not unlike yours, and I've never gotten into any significant trouble from drinking. For now, I don't care if I'm an alcoholic. I know I'm better off not drinking at all, so that is what I've chosen to do.