How do you know you're in love?

Sarah • I'm 22, in a relationship, and I want to be more positive in my life. Twitter: @piespice
I'm in a relationship right now and it's fairly new (almost 2 months old). We moved really fast, I lost my virginity to him (I'm 20), and I don't know if I'm in love with him or not. I feel completely different about him than I did about any of my past boyfriends. I just don't understand what being in love feel like I guess.