Where did my period go?

Ok, so i'm 24 and up until 10 months ago my period was always every other month, well around new years eve was my last period. I went to my obgyn, she did a pap, ran blood work, did an ultra sound and except for a few small uterine fibroids everything came back normal so she put me on the nuva ring, I used it for the 3 weeks, took it out 5 days ago and still no period.....I'm pretty sure i'm too young for menopause so what could it be? I just want to get it already