if you vomited any less than 2 hours after taking your pill, then it didn't have the time to absorb into your body and that means you weren't protected and should have used an emergency contraception. It's possible you could be pregnant, but the brown discharge sounds like old blood that didn't make its way out last period. Wait for a missed period and then take a pregnancy test!!
Since I had been taking the Yaz for almost two months straight (I skipped my period by not taking the placebo pills) do you think this changes the possibility of me being unprotected?