The last few months I have been having two periods each month. I'm currently on birth control and have been for about 11 months, and I get my regular period on the placebos. But the last few months I get a second menstrual cycle two weeks after the placebos. The cycle is very light, barely staining my panties and really only noticeable when I wipe.

8 months ago my gyno thought I had an ovarian cyst, but found nothing after an ultrasound.

My older sister had pretty messed up periods after her 3rd child and ended up having quadruplets naturally, no fertility drugs. I have not had any children.

What is the reasoning for 2 periods in a month? Is there something wrong or am I just doomed to have all of my children at once?