(( VaginaPagina ))

It could very well just be spotting. Sometimes I will spot on BC just randomly. Honestly, the added physical stress of smoking might contribute to that -- not that your body is directly processing the tar through your vagina, but that the strain of processing the chemicals and tar has kicked your hormone balance a little weird, and caused spotting. You're under other physical stresses too -- traveling, the anti-malarials, the food/water change -- and maybe this is just the point where you're starting to see the effects in your cycle.

(P.S. -- just fyi, it's actually "kegel" and "phlegm." Those are both such weird words!)