Should I be worried?

I may sound crazy but, my husband has gotten a whole lot better with sex recently, out of no where. We have been together for over 7 years, married since February and his performance in bed has never been the way that it has become recently. Should I think that my husband is sleeping with another woman because of these new skills or should I just embrace how great his has become? (It is beyond great). Has this happened to anyone else?