Here is a thread you might look at.
Basically, its not the lemonade but the SWF (Salt-Water-Flush)
and lax tea which would have an impact on the efficacy of your pills. It is best to use protection during this time to insure you do not have an unwanted pregnancy at a time when it would not be optimal to conceive.
On the front page of the Curezone, you can find a search engine box. If you put in birth control and MC, you will find more posts which may be relevant.
I wish you well~~
The Master Cleanse