(( VaginaPagina ))

'K, you're right, almost nothing is completely impossible, but having (unfortunately) been a smoker for seventeen years, if this was possible I would expect to have experienced it before, or at least heard of it. I have heard of people, especially those on BC, having extreme bouts of thick brown to black discharge, so I'm still relatively sure that's what you are experiencing, as apposed to tar-crotch.