OK, so I did a little research... I found a site that talks about
why we need probiotics. It states that birth control pills (among other things) can disrupt the flora in our digestive systems. Hence, probiotics are good to take. I assume if probiotics are good to take while on birth control then they wouldn't have any affect on the "control" part. Here is the website:
http://www.healingdaily.com/detoxification-diet/probiotics.htm