Hi. I don't know if anyone here has any knowledge of this, but I thought I'd try. Here I go, out with it. I have this toe fungus thing under one of my toe nails. For this my GP recommended Terbinafine which is like lamasil, I guess. Anyway, I've always had regular periods, right on track, until a month after I started taking the Terbinafine. 1 month into the meds, and my period started coming every 1.5 - 2 weeks! I have also been stressed during this time so it could be that. I just wondered if anyone knew anything about this drug, cycles and conception. I'd love some input.