No you don't have a sexually confused puppy. My Mikki did the same thing. And I posted the very same question.
I was shocked too!! Believe it or not it does go away. Or at least it did with Mikki. After she was fixed and lots of redirection and no ma'ams. She doesn't hump at all any more. If I remember correctly, in my post they told me it was a dominance thing. Maybe someone who posted on mine will tell you what all they told me. I will try to find my old thread as well. Don't worry mommy, she is ok.