Pregnancy scare, broken condom!

So here's the story... About a month and a half ago, my girlfriend and I had protected sex, but when I pulled out, the condom was broke! We of course both freaked out, and I thought she was on birth control. Well. She was on birth control three weeks prior, but stopped. She took Plan B 5 hours later, and a week later she had her period, full blown, 5 days long, but it was a more liquidy period? Well. A month later, we have continued to have protected sex, condom every time, and I pull out, taking every precaution. She started taking her b***h control more frequently now, on a daily basis again. A week ago she complained of being bloated and she had sore breasts, and of course we freaked. Now, she has had her period for about 3 days when she realized its stopped, and she said that it was a dark brown color, with a little bit of red on the second day and almost nothing the third. She isn't bloated, but she said her breasts are sore. Could she possibly be pregnant? I'm mature enough to know that whenever we have sex we take that risk, but could this be side effects from the Plan B? Combined with her starting her BC again? Or is it a possible preagnancy. Any help would be great!