I've been on bcp's over a year now, so it wouldn't make sense for it to suddenly be shortening my period. The mistake I made was skipping week two of the pills, on accident. I took the last pill of week one and then (through a switcheroo of packs because I forgot mine at home) I took the first pill of week three, and so on. I didn't discover this mistake until week two... Of the next month. Because I figured "hey, this new pack, I started half way through. I'll just start up with week one of this pack, take it until the point in which i'd done the switch over, and everything will be copasetic and I won't have wasted two half-packets of pills. I get to the end of week two, because that's how much was in the pack, and go back and look at the old pack, since it should only have week three pills, because that's where I thought I was, so that's where i'd started on the new pack. Well, the old pack had, terrifyingly, all of week two still in it, which means when I picked upthe new pack, i'd skipped week two. Well, I didn't take all of these week two pills, because this time around, that would have meant that i'd be taking two weeks of week-two pills, and that's not good, since I was supposed to be starting week three now, as I had just finished week two on the other pack. So I went on to week three, and since I had the packets to compare, I knew this time that I was actually right. But of course now, I knew that last month my cycle had only consisted of week one and week three pills, so I freaked out, even though i'd gotten a totally normal period. Now, it's been that whole normal month of taking the pills the right way, and i've had yet another period. However, this one was lighter, not by much, and lasted three and a half days, which is about a day shorter than normal. I also had unusually heavy discharge last month, that stopped promptly when I got onto the week three pills. I am on week one pills once again, and my discharge has been a little heavy, but nothing too unusual, not yet anyway.