Hello all! I'm new to the boards and wanted to ask a couple questions. I've been on Ovcon 35 for a little over a year. I recently got changed to Balvisa (about 3 months ago). I am a relatively healthy 20 yr. old but often times my pill makes me feel sick. I often get stomach aches and nausea. I take it at the same time every night (within 15 minutes), and have never missed a pill. My questions are, I get break-through bleeding in almost every month, especially after intercourse. What could be the cause of this? And because there is break-through bleeding, is there a chance that unprotected sex could result in pregnancy? Thank you for your time!