So I've been using birth control for about 3 years, and my doctor prescribed me a BCP called Lo Lesterine Fe (It's a low dose BCP) and I've been using it for a couple months now with no problem at all. I stopped using it for a month, and got back on it again. It hasn't been a full week of using it, but my boyfriend and I had sex without a condom. I've read to ALWAYS use a backup (like a condom), but with my situation, I was wondering if you can use the Plan B pills as a back up as well. Or will that cause complications if I'm using the BCP at the same time?