slept with. 3 people and I'm considered loose

I'm 21 years old and I've had sex with only 3 people. The three men I've had ssx with were people I was very serious about. Currently I'm in a relationship and I'm only loyal to him. My family is concerned about me going away to college. They consider me easy and "loose". I got very pissed off because I've only had sex with three men. The third being my bf. I told them if I had sex with someone one day and a different guy the next, that would be different. But when I'm in a relationship, it's only with one person. It just got me so upset and mad. They tell me I don't take it seriously. Every time I have sex, it's always safe and I don't take risks. Am I really considered easy?