I'm using the Aviane 28 day for my BC. And I have PCOS, incase this might have something to do with this. My problem is that I've been on these since April of 2015, and have experienced a few months where I don't have a period when I'm on the last week of pills. The first time was in October and I was on an antibiotic and took a test, which came up negative. November was the same and tested negative. Now this month I didn't have my period and I start new pack tomorrow. I tested again because I did miss a couple days but test was negative. Has this happened with anyone? Is it normal for periods to disappear on this pill? I think it's safe to say I'm not pregnant and no other health problems exist.