there was 'slightly' mitigating circumstances tho.....
I started on the back-to-back in january, while on anti-b's for tonsilitus.
I needed to do the back-to-back for the peiods arriving at inoportune times, and altho I knew that the anti-b's would effect the pill, I thought it would effect just the january pack. used condoms for january, but from feb onwards thought I would be covered......
when I stopped the pill to have my april period, I was pregnant......and she came in december, so I fell for her either at the very end of feb, or march!!!!
docs said that the anti-b's effected the whole 3 packs of the pills I took cos I didn;t take the break.....
taught me a lesson, altho it WAS a wonderful lesson (most of the time).
sooo......if you need anti-b's. take care for the entire time until you get the next period!