Actually, if you had breakthrough bleeding before the pill, it is usually a hormonal imbalance caused by low progesterone and going on the pill tends to make it worse by upping the ratio of estrogen to progesterone in the body. You might try going off the pill again (with your family history of breast cancer it might be wise anyway). Then, note where in your cycles the bleeding occurs--is it around mid-way (ovulation--it's actually normal to spot then) or is it in the 2 weeks between ovulation and your period? If it's in the luteal phase (the time between ovulation and your period), it's almost definitely a low progesterone situation. There are some things you could try--taking vitex (chaste tree berry), taking 100-200 mg vitamin b6 daily (sometimes this defect is caused by low vitamin b6, but don't take more than 200 mg of it daily, it's dangerous in higher doses--good to take it in a b vitamin complex since all the b vitamins work best together), trying natural progesterone cream. Or, if the spotting is still bad, see about testing your progesterone 7 days past ovulation (cycle day 21 for a 28 day cycle usually) at the gyno or an endocrinologist. They can prescribe progesterone supplements. Good luck to you!
Another thing that might help if you go off the pill is charting your cycles (basal body temperatures). This is used by a lot of women trying to conceive or using fertility awareness method to avoid pregnancy. If you have a short luteal phase (less than 10 days), that's almost a red flag for low progesterone. I have had low progesterone since stopping bcps 7 months ago, that's how I know so much about it, unfortunately. If you're interested in this, the site
http://www.Fertilityfriend.Com
has info on how it works and lets you chart online for free. If you suspect you might have low progesterone, it might be worth it to chart and see what your cycles do.
