abnormal uterine bleeding
"I started this birth control about a month ago after bleeding non-stop for four months (have PCOS) and it stopped my bleeding immediately, however in about the second week I began having mild cramps and spotting brown.  I missed the last pill of my third week and took it the next morning - and bam, there was the heavy bleeding again. The bleeding and clotting is awful. If the bleeding doesn't stop after I start my new pack, I think I'm going to switch.

As for other side effects, none!"