I am in the middle of my third pill pack and have not missed a pill. I have never taken birth control pills prior to this, so I am having a hard time telling if I am experiencing side effects of the pill or if I should be worried I am pregnant. My breasts are tender and seem swollen at times. The first two pill packs I had breakthrough bleeding, but this month I have not. I have had cysts/cramps in the past and I am experiencing some pain this month. I am experiencing some minor lower back pain, too. I have not experienced nausea or migranes, but do have a minor discharge. I am prone to yeast infections, but all of these things combined are making me nervous. Should I be worried?