Does anybody else have a naturally low sex drive?

I'm 21 and at my sexual and physical prime. Boyfriend and I have been dating for 6 years. We are still madly in love and keep things VERY interesting in the bedroom. Nice and spontaneous. Occasionally I'll have random urges but otherwise nothing. I've gone to my gyno (who suggested lube? Like I've never tried that before?). Then during one of my classes this really attractive guy started flirting with me. It lasted for weeks. I started fantasizing about him to see if my relationship with my SO had run its course and still...nothing happening in my lady regions. No man (or woman) has made me feel anything in a long while. I've never in my life felt the need to masturbate either. Ive tried but it didn't get me going. Occasionally (about once every few months) I'll have a wet dream.