I have been on the pill for 6 years now and I often experience breakthrough bleeding, which often lasts 2-3 weeks at a time. My several gynae's over time, have tried differentspills but nothing seems to change what happens. I am however, on other medication such as Topamax, Molypaxin and Wellbutrin and my gynae is aware of this. I also know that these cann have an effect on the pill, but why does it only happen from time to time? What I would also like to know is with all this happening, does it increase my chances of falling pregnant even though I am on the contraceptive pill? (I am currently on Yasmin). I am currently not sexually active because I fear that that the effectiveness of my contraception is reduced and I would like your advice on the matter.