Maybe you need a higher dosage of estrogen. I was on low dose b/c after my son so I could still breastfeed only I bled for a YEAR after having him. Anything with high levels of estrogen gives me a raging headache. After much poking and prodding And being cleared for no tears, rips, left over placenta they changed my birth control. It took a few different kinds to find the right one (I would stop bleeding, have sex then continue to bleed) but finding the right combo without side effects was key. Nothing like bleeding when your not supposed to!