Hi, I am the same. I hardly ever have periods on my own, I would have probably had about 6-8 natural periods on my own in about 8 years. Even then, about 4 of them were when I first started back when I was a teenager. The only time that I would ever have a period was when I was either on the pill (regular like clockwork) and when I was given a course of tablets which would enduce a period (i.e. Provera and the like). I was given Provera a few years back hoping that it would kick start everything, and that just never did! When I first got diagnosed, I was told by the vag man (gynae) that he thought I was ovulating, but I was never able to conceive as I never had periods. So, finally, after moving away and then having to have to go through all the apps again with different Drs/FS's I have finished my first round of Clomid (100mg's like you too), after taking Provera to force on a bleed, and I am just waiting in limbo now as to whether I am going to have a natural AF if I have not conceived this month. I have a funny feeling I could still be sitting here at Christmas 2012 waiting for AF to show! I know exactly how you feel, as I am in the same boat as you. I am 22, so not much older than yourself.
Keep your chin up - we will get there one day! x