Sex in high school...

Soo....i feel like I'm the only virgin in my school. Everyone around me has had sex. And when people ask me " have you ever had sex?" I used to say "No. Im virgin." Then they would start, I guess sort of...slightly teasing me. So now when they ask me that question I just say " Yeah, I've done it before." Or "No. I'm not a virgin" when in reality I really am. Has anyone ever experienced this? Do you have any advice on how to handle a situation like this? Also if you don't mind answering this question, When did you lose your virginity?