i was on a good BC pill and when i started my inactive pills, my peroid never started until the 3rd day of them. its just your cycle and it was all good for me for a couple years! But, my pills DID let me have a lighter and less painful period...not sure about the bigger boob theory... the pills i was on were low ovral dos. maybe look into that or ask your Doc about that name they were good for me. good luck