I was on it for a little over two years and never had a period, and got pregnant while on it. I ended up having a miscarriage at 14weeks because the medicine was still in my system and effected the babies growth.

I was on it for 9 months and only spotted while I was on it. then I went like 6 months with no period after I stopped it and a year or so with irregular periods.

I never even got my period on it and I was in it for 5 years :) normal