Have you had sex with someone else previously? Sounds like it might be someone else's, if you have. Do have a women's clinic near you? You need to have a pregnancy blood test. That's more dependable. I doubt very much that it was the sex from the week before. That's awfully quick to get a positive. Please see a counselor before you approach this man. Also, 16 is too young to be drinking with boys in their 20s. Your life experiences don't relate. Be careful. Pat