Can mucinex interfere with birth control?

I've had a cold, been taking maximum strength mucinex, and today I began experiencing breakthrough bleeding even though I've taken my birth control on time the entire week. I use the pill, a brand called Necon. I am aware some medicines can interfere with the effectiveness of birth control, I wasn't sure if mucinex was one such drug. Anyone know? I looked on their website and couldn't find any information on it, I guess it's not exactly something they feel the need to address ^_^;;.