We are going on a trip in June and I wanted to stretch my period with one week so that I won't have my period during our trip. I went on a new pack for another week, we had unprotected sex on my ovulation date while I was using the pill. Yesterday, and this morning I've had a brown discharge, could pregnancy be a possibility or is it normal because my period should have started today?

Take a pregnancy test to be sure, but it sounds to me like you're probably just spotting.