Is my wife cheating on me?

I have always trusted my wife but now I am beginning to wonder a little. In the past few months I have noticed some changes that really make me wonder. For the past five years she has worn her hair quite short, partly because I like it, but mostly because she looks really good in short hair. All of a sudden about three months ago she decided short hair is gross and wants to grow it long. About two months ago she began going out dancing one night a week, I bow out because I am a recovering alcoholic, and barrooms aren't a good place for me. She comes home very late, very intoxicated.She has begun to change her wardrobe as well as different underwear.Also she recently decided that she needs a cell phone.There is a definite coolness in the atmosphere at home now that I can't put my finger on. Am I being paranoid or could there be something there?