What am I doing wrong? What should I do?

For almost all my life I have firmly believed in keeping my studies and career my first priority above everything else. I'm 19 and I'm finally going to med school.Of course, I am open to having a relationship. I don't mean to be vain but I am quite attractive. Guys compliment and check me out all the time but no one wants to be in a relationship with me even though I'm the last person you would call slutty. I feel like everyone my age has lived their life and even though I have accomplished a alot academically I have done nothing when it comes to personal relationships. Literally nothing. I have had one "boyfriend" when I was 17 and that too for a week. I'm not even the "needy" type of girl. I in fact give too much of space. I'm starting to feel something is radically wrong with me. My one friend told me that maybe the right person hasn't come yet. I don't believe in that. That's just fodder for people who want some kind of hope to cling on to. What am I doing wrong?