(( VaginaPagina ))

The uterus and the ovaries are entirely not talking to each other when you're on HBC, so unless your pill-taking is compromised by days of no-hormones, the bleeding is more likely to be that your uterus decided it wanted to shed a little something for some reason. An hour-late pill will do it for some people! (Though the ovaries don't care about an hour; they care about, y'know, 12-24 hours, or maybe even 48 hours.) If you're under stress, that can do it. And sometimes the uterus just does breakthrough bleeding for no obvious reason; the uterine lining becomes thinner and often more fragile, when on HBC, and anything that's knocked some loose (e.g., an orgasm, bouncy exercise, etc.) will cause spotting.