My last period was super light pink over a day and a half instead of it's usual 3-4 days. I had just finished my third pack of BC pills. The period before that was quite heavy and the one before (1st pack) was light but not nearly as light. Any cause for concern? I had taken one pill about 7 hours late two weeks or so before this super light period but all others were within 20 mins of my time if not on time.