I have been on seasonale for 3 months & really like it. I have read through some of the posts and I think that I can address some of the questions out there.
Pms time-span:
on my old pill (ortho-novum 1/35) I started my pms 10-12 days like clock-work before my period. So, I don't think it's abnormal. I was on that pill for 8 years. I haven't had my first period yet with seasonale but it'll be here in 2-3 weeks. We'll see what happens then.
Break-thru bleeding:
I had only one break through bleeding event in the first month when I would normally have had my period & it only lasted 1 day. I was warned quite extensively that it was common to get & that it happened a lot with some women...But no problems here.
Chest size : I have noticed no difference at all & I didn't really expect to.