You dont want to get this information here. Why? Because there is so much propaganda out there that you can find sources that will go both ways, you will find ones that will say yes something bad happens and you will find ones that say no, something bad definitely does not happen.
Google search something like "Marijuana effects on birth control users" and try to find a page of correlations. To be honest, I have never seen a page of info or a study that specifically addressed marijuana users who were on the pill, but I would hedge a bet that pot does not affect you badly any more or less if you are on birth control, else there would be alot more information to the effect. Hormones via BC and THC from pot seem to be relatively unrelated.
Although, depending upon the hormones, it could be considered to lower the effectiveness of birth control. I know a host of other things, even a night of heavy drinking can throw BC off and increase the chances of pregnancy. So its possible someone has done a study on that.
Search some medical websites, you wont find information accurate enough for your purposes here. I know a ton about various substances and medical issues from self research and I cant even provide you a definite answer to this specific question. [ WittyUsernameHere's advice column | Ask WittyUsernameHere A Question ]
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