Some guys like shorter hair a lot more while some guys do not and prefer girls with longer hair. So in general: no. To guys that prefer longer hair: maybe. For guys that have a thing for longer hair, you can still be very attractive, but would probably even more attractive with longer hair. In any case, do whatever you prefer!
Girl I feel the same way! I got my hair cut this summer due to it having gotten frazzled from medication. It used to be down to my waist, now it's a little below my shoulders! And I find myself missing it long!! But honestly, I think we've got more attributes than our hair. We're women for gosh sake, we've got tons of attributes!