I started taking GC extract pills just this week. Overall, I took about 5 pills (1 on Monday night, 2 on Tuesday, and 2 on Wednesday). I started breakthrough bleeding Friday evening of the same week, despite taking all my birth control (tricira lo 28) pills on time. I have been taking my birth control pills for over a year now and my menstrual cycle is regular, so breakthrough bleeding is out of the ordinary. My period shouldn't have come for at least 9 more days, so I definitely suspect that this was caused by the GC extract pills. This is my second day without taking GC, so I'm hoping the breakthrough bleeding will stop soon.