am i pregnant?

I've been steady with a guy for 2 months now. Every time we have sex it's with a condom. One time in mid july the condom broke and we *immediately* went and got a plan B. I'm on birth control and take it pretty regularly (if not at the same time, within an hour or so at the latest) and i usually have normal-heavy periods. My july period was a bit light and wonky and i just put that off thinking it was the plan B effect. I've continued taking birth control on time this month and during the placebo week, my period only lasted for 2.5-3 days... i had a bit of bleeding and small clots for 2 days but then blood discharge was more brown in color.

could I be pregnant?